GMAT Critical Reasoning

CR Question 48, 49

2009-03-11T11:48:00.003+08:00

48). Black Americans are, on the whole, about twice as likely as White Americans to develop high blood pressure. This likelihood also holds for westernized Black Africans when compared to White Africans.
Researchers have hypothesized that this predisposition in westernized Blacks may reflect an interaction between western high-salt diets and genes that adapted to an environmental scarcity of salt.

Which of the following statements about present-day, westernized Black Africans, if true, would most tend to confirm the researchers' hypothesis?

(A) The blood pressures of those descended from peoples situated throughout their history in Senegal and Gambia, where salt was always available, are low.

(B) The unusually high salt consumption in certain areas of Africa represents a serious health problem.

(C) Because of their blood pressure levels, most White Africans have markedly decreased their salt consumption.

(D) Blood pressures are low among the Yoruba, who, throughout their history, have been situated far inland from sources of sea salt and far south of Saharan salt mines

(E) No significant differences in salt metabolism have been found between those people who have had salt available throughout their history and those who have not.

49). The spacing of the four holes on a fragment of a bone flute excavated at a Neanderthal campsite is just what is required to play the third through sixth notes of the diatonic scale—the seven-note musical scale used in much of Western music since the Renaissance. Musicologists therefore hypothesize that the diatonic musical scale was developed and used thousands of years before it was adopted by Western musicians.

Which of the following, if true, most strongly supports the hypothesis?

(A) Bone flutes were probably the only musical instrument made by Neanderthals.

(B) No musical instrument that is known to have used a diatomic scale is of an earlier date than the flute found at the Neanderthal campsite.

(C) The flute was made from a cave-bear bone and the campsite at which the flute fragment was excavated was in a cave that also contained skeletal remains of cave bears.

(D) Flutes are the simplest wind instrument that can be constructed to allow playing a diatonic scale.

(E) The cave-bear leg bone used to make the Neanderthal flute would have been long enough to make a flute capable of playing a complete diatonic scale

Answers:

48). OA - A
http://forum.prachipareekh.net/viewtopic.php?f=24&t=556

49). OA - E
http://forum.prachipareekh.net/viewtopic.php?f=24&t=138

CR Question 46, 47

2009-02-18T10:58:00.000+08:00

46). For the past 13 years, high school guidance counselors nationwide have implemented an aggressive program to convince high school students to select careers requiring college degrees. The government reported that the percentage of last year's high school graduates who went on to college was 15 percent greater than the percentage of those who graduated 10 years ago and did so. The counselors concluded from this report that the program had been successful.

The guidance counselors' reasoning depends on which one of the following assumptions about high school graduates?

(A) The number of graduates who went on to college remained constant each year during the 10-year period.

(B) Any college courses that the graduates take will improve their career prospects.

(C) Some of the graduates who went on to college never received guidance from a high school counselor.

(D) There has been a decrease in the number of graduates who go on to college without career plans.

(E) Many of last year's graduates who went on to college did so in order to prepare for careers requiring college degrees

47). Frobisher, a sixteenth-century English explorer, had soil samples from Canada's Kodlunarn Island examined for gold content. Because high gold content was reported, Elizabeth I funded two mining expeditions. Neither expedition found any gold there. Modern analysis of the island's soil indicates a very low gold content. Thus the methods used to determine the gold content of Frobisher's samples must have been inaccurate.

Which of the following is an assumption on which the argument depends?

(A) The gold content of the soil on Kodlunarn Island is much lower today than it was in the sixteenth century.

(B) The two mining expeditions funded by Elizabeth I did not mine the same part of Kodlunarn Island.

(C) The methods used to assess gold content of the soil samples provided by Frobisher were different from those generally used in the sixteenth century.

(D) Frobisher did not have soil samples from any other Canadian island examined for gold content.

(E) Gold was not added to the soil samples collected by Frobisher before the samples were examined.

Answers:

Best approach for such questions is to negate the assumption and then look what effect this creates on the conclusion

46). OA - E

1st Premise: High school guidance counselors nationwide have implemented an aggressive program to convince high school students to select careers requiring college degrees

2nd Premise: The government reported that the percentage of last year's high school graduates who went on to college was 15 percent greater than the percentage of those who graduated 10 years ago and did so.

Conclusion:The counselors concluded from this report that the program had been successful.

Using deniel test: Many of last year's graduates who went on to college did not prepare for careers requiring college degrees - if this was true can we draw the conclusion that the program was successful - No, because then the very purpose of the program gets defeated(high school guidance counselors nationwide have implemented an aggressive program to convince high school students to select careers requiring college degrees), hence the program would have not been a success

47). OA - E

Using deniel test: Gold WAS added to the soil samples collected by Frobisher before the samples were examined.

If the above statement was true, can we draw the conclusion that method was inaccurate -- No, hence E must be the answer

Why not C: Methods were different. So what? Does it prove or deny the conclusion that method was inaccurate? No ..hence ruled out.

CR Question 45

2009-01-19T17:59:00.000+08:00

Nearly all mail that is correctly addressed arrives at its destination within two business days of being sent. In fact, correctly addressed mail takes longer than this only when it is damaged in transit. Overall, however, most mail arrives three business days or more after being sent.

If the statements above are true, which one of the following must be true?

A) A large proportion of the mail that is correctly addressed is damaged in transit

B) No incorrectly addressed mail arrives within two business days of being sent

C) Most mail that arrives within two business days of being sent is correctly addressed

D) A large proportion of mail is incorrectly addressed.

E) More mail arrives within two business days of being sent than arrives between two and three business days after being sent

Answer: D

OE: This is a tricky question because it asks the test taker to come to a conclusion that is obviously false in real-life (but standardized tests aren't real life).
The question tells us that nearly all mail that is correctly addressed arrives within two business days. The only mail that doesn't arrive within two business days must be damaged mail and incorrectly addressed mail. Because we know that nearly all correctly addressed mail is not damaged, the fact that most mail arrives three business days or more after being sent can be read to indicate that there is a very large number of incorrectly addressed mail, which is answer (D).

A - incorrect - because the question states that 'overall, most mail arrives within three days,' indicating that a small amount of mail was lost.

B - incorrect - the passage contains no information to rule this possibility out.

C - incorrect - the passage tells us that if a piece of mail is correctly addressed that it will arrive within two days, assuming that there is no damage. But, if a large proportion of mail is incorrectly addressed (see D), then it is possible that (C) is not true since a large proportion is not correctly addressed.

E - incorrect - There is no evidence of this in the statement or way to deduce it.

CR Question 44

2008-12-15T22:02:00.000+08:00

The fact that several of the largest senior citizens’ organizations are constituted almost exclusively of middle-class elderly people has led critics to question the seriousness of those organizations’ commitment to speaking out on behalf of the needs of economically disadvantaged elderly people.

Which of the following generalizations, if true, would help to substantiate the criticism implicit in the statement above?

(A) The ideology of an organization tends reflect the traditional political climate of its locale.

(B) The needs of disadvantaged elderly people differ in some ways from those of other disadvantaged groups within contemporary society.

(C) Organized groups are better able to publicize their problems and seek redress than individuals acting alone.

(D) Middle-class elderly people are more likely to join organizations than are economically disadvantaged elderly people.

(E) People usually join organizations whose purpose is to further the economic, political, or social interests of their members

Answer: E

OA - E

1st Premise: Organizations consist of more elderly middle class citizens
2nd Premise: Organizations' are committed to speak out on behalf of the needs of economically disadvantaged elderly people.

Conclusion: If organization doesn't speaks out on behalf of the needs of economically disadvantaged elderly people then its members are probably not economically disadvantaged

Option strengthening the conclusion

E - People usually join organizations whose purpose is to further the
economic, political, or social interests of their members => least bothered about the economically disadvantaged people, so will not speak out for them.. just the interest of middle class elderly reigns

(A) The ideology of an organization tends reflect the traditional political climate of its locale. - political climate ?? irrelevant

(B) The needs of disadvantaged elderly people differ in some ways from those of other disadvantaged groups within contemporary society. - out of scope - not interested in other disadvantaged groups

(C) Organized groups are better able to publicize their problems and seek redress than individuals acting alone. - is this affecting our conclusion in any way ? No - irrelevant

(D) Middle-class elderly people are more likely to join organizations than are economically disadvantaged elderly people. - more likely to join ?? - may be - but is this affecting our conclusion in any way? No - irrelevant

CR Questions 42, 43

2008-05-03T17:45:00.000+08:00

42). Toddlers are not being malicious when they bite people. For example, a child may want a toy, and feel that the person he or she bites is preventing him or her from having it.

The situation as described above most closely conforms to which one of the following generalizations?

(A) Biting people is sometimes a way for toddlers to try to solve problems.

(B) Toddlers sometimes engage in biting people in order to get attention from adults.

(C) Toddlers mistakenly believe that biting people is viewed as acceptable behavior by adults.

(D) Toddlers do not recognize that by biting people they often thwart their own ends.

(E) Resorting to biting people is in some cases an effective way for toddlers to get what they want.

43). Psychiatrist: We are learning that neurochemical imbalances can cause behavior ranging from extreme mental illness to less serious but irritating behavior such as obsessive fantasizing, petulance, or embarrassment. These findings will promote compassion and tolerance when looking at a mental illness, quirk, or mere difference between two persons, since being mentally healthy can now begin to be seen as simply having the same neurochemical balances as most people.

Which one of the following most accurately expresses the conclusion of the psychiatrist's argument?

(A) Understanding the role of the neurochemical in behavior will foster empathy toward others.

(B) Neurochemical imbalances can cause mental illness and other behaviors.

(C) Neurochemical balances and imbalances are the main determinants of mental behavior.

(D) Being mentally healthy is a matter of having the same neurochemical balances as most people.

(E) Advances in neurochemistry enhance our theories of mental illness

Answers:

42). OA - A

Conclusion: Toddlers are not malicious when they bite other people. The stated example tells the fact that why the toddler feels his act of biting is acceptable and that he would get what he wants by biting

A - correct - similar to reasoning above - toddler bites to get a toy ..thus in a way solves his problems
B - incorrect - irrelevant - nowhere adults are mentioned in the argument
C - incorrect - irrelevant - no feelings of Toddlers towards adult is stated in the argument
D - incorrect - does not relates to the argument though can be true
E - incorrect - how do we know it is an effective way..it is not stated in the argument

43). OA - A

We are suppose to identify the conclusion

A - correct - expresses the conclusion: These findings will promote compassion and tolerance....
B - incorrect - this is not a conclusion but simply a fact.
C - incorrect - main determinants - nowhere stated
D - incorrect - this is same as a fact
E - incorrect - close call but too broad to conclude..A is better than E

CR Question 40, 41

2008-04-05T01:45:00.000+08:00

40). A researcher discovered that people who have low levels of immune-system activity tend to score much lower on tests of mental health than do people with normal or high immune-system activity. The researcher concluded from this experiment that the immune system protects against mental illness as well as against physical disease.

The researcher's conclusion depends on which of the following assumptions?

A. High immune-system activity protects against mental illness better than normal immune-system activity does.

B. Mental illness is similar to physical disease in its effects on body systems.

C. People with high immune-system activity cannot develop mental illness.

D. Mental illness does not cause people's immune-system activity to decrease.

E. Psychological treatment of mental illness is not as effective as is medical treatment

41). Twenty years ago the Republic of Rosinia produced nearly 100 million tons of potatoes, but last year the harvest barely reached 60 million tons. Agricultural researchers, who have failed to develop new higher yielding strains of potatoes, are to blame for this decrease, since they have been concerned only with their own research and not with the needs of Rosinia.

Which one of the following is an assumption on which the argument depends?

(A) Any current attempts by agricultural researchers to develop higher-yielding potato strains are futile.

(B) Strains of potatoes most commonly grown in Rosinia could not have produced the yields last year that they once did.

(C) Agricultural researchers often find concrete solutions to practical problems when investigating seemingly unrelated questions.

(D) Wide fluctuations in the size of the potato crop over a twenty-year period are not unusual.

(E) Agricultural research in Rosinia is funded by government grants.

Answers:

40). OA - D

Best approach for such questions is to negate the assumption and then look what effect this creates on the conclusion

Conclusion: immune system protects against mental illness
Negate the assumption: Mental illness causes people's immune-system activity to decrease.

Argument is shattered

Why not B:

Mental illness is similar to physical disease in its effects on body systems. - Assumption. Mental illness is similar to physical.

Now if you negate this assumption then the conclusion that "Protects against mental AND physical" falls ---- the similarity b/w the two diseases needs not be true for the immune system to work as claimed. The immune system can protect against two mutually exclusive diseases and still be effective. It's like saying that tylenol protects against headaches and depression. Are the two similar? Not at all. Yet, tylenol can still protect people against the two.

41). OA - B

Follow denial technique for assumption questions -

Negate : Strains of potatoes most commonly grown in Rosinia could have produced the yields last year that they once did. If this is true, then there could be some other reason for the reduced harvest. However, since the strains could not produce the same yields last year, the researchers are to blame for the poor quality of the strain

CR Question - 39

2007-03-02T19:21:00.000+08:00

39). The media claim that the economy is entering a phase of growth and prosperity. They point to lower unemployment rates and increased productivity. Their analysis is false, though. The number of people filing for bankruptcy has increased every month for the last six months and bankruptcy lawyers report that they are busier than they have been in years.

Which of the following is an assumption on which the argument depends?

A. Unemployment rates are not useful indicators of growth and prosperity.
B. Economic growth cannot be measured in terms of productivity.
C. Legislation has not been recently passed to make legal bankruptcy easier to obtain.
D. There has not been an increase in the number of bankruptcy lawyers.
E. The media often misrepresent the current state of economic affairs.

OA and OE : From MGMAT CAT1

OE: The conclusion of the argument is that the media are wrong in saying that the economy is entering a phase of growth and prosperity. The basis for that claim is that the number of people filing for bankruptcy has increased every month for the last six months and that bankruptcy lawyers are busier than they have been in years. In order for this argument to be valid, however, the author has to assume that the increase in the number of bankruptcies is a result of the state of the economy and not the result of something unrelated.

(A) This does not have to be true for the claim that the media are wrong about the economy to hold. It is possible that unemployment rates are useful indicators of growth and prosperity and that media is still wrong about the economy (i.e. if there are other indicators that show problems in other areas).

(B) This does not have to be true for the claim that the media are wrong about the economy to hold. It is possible that productivity is a good measure of economic growth and that media is still wrong about the economy (i.e. if there are other indicators that show problems in other areas).

(C) CORRECT. This has to be true for the claim that the media are wrong about the economy to hold. If legislation has recently been passed that makes it easier to obtain bankruptcy, this would explain away the counterevidence to the media's argument. The increased number of bankruptcies could have been the result of the easier process rather than of a poor economy.

(D) This does not have to be true for the claim that the media are wrong about the economy to hold. An increase in the number of bankruptcy lawyers would not explain the increase in the number of bankruptcy filings.

(E) This does not have to be true for the claim that the media are wrong about the economy to hold. Even if the media did not often misrepresent the current state of economic affairs, the argument that the media are wrong might still hold.

The correct answer is C.

CR Questions 37, 38

2007-02-27T01:23:00.000+08:00

38). In experiments in which certain kinds of bacteria were placed in a generous supply of nutrients, the populations of bacteria grew rapidly, and genetic mutations occurred at random in the populations. These experiments show that all genetic mutation is random.

Which one of the following, if true, enables the conclusion to be properly drawn?

(A) Either all genetic mutations are random or none are random.

(B) The bacteria tested in the experiments were of extremely common forms.

(C) If all genetic mutations in bacteria are random, then all genetic mutations in every other life form are random also.

(D) The kind of environment in which genetic mutation takes place has no effect on the way genetic mutation occurs.

(E) The nutrients used were the same as those that nourish the bacteria in nature.

38). In the effort to fire a Civil Service employee, his or her manager may have to spend up to $100,000 of tax money. Since Civil Service employees know how hard it is to fire them, they tend to loaf. This explains in large part why the government is so inefficient.

It can be properly inferred on the basis of the statements above that the author believes which of the following?

I). Too much job security can have a negative influence on workers.
II). More government workers should be fired.
III). Most government workers are Civil Service employees.

Answer choices :

(A) I only
(B) I and III only
(C) II only
(D) I, II, and III
(E) III only

Answers --

37). OA - A - The genetic mutations in the experiment were random and therefore all genetic mutations have to be random, drawing the conclusion that all genetic mutations are random.

B - incorrect - what if the impact of environment is greater than the type of bacteria used.

C - incorrect - If all genetic mutations in bacteria are random, then all genetic mutations in every other life form are random also --- The experiment does not show that all genetic mutations in bacteria are random and therefore the conclusion that all genetic mutations are random can't be drawn.

D - incorrect - there may be other factors apart from environment which may affect the way mutations occur in other instances.

E - incorrect - What if the bacteria is different in nature than from that given in the experiment?

38). It is A

Premise: It is hard to fire Civil Service Employees.

Conclusion: This explains in large part why the government is so inefficient.

Assumption: The total number of civil service employees in the goverment is large/more

III.Most government workers are Civil Service employees - this is just the reverse of assumption - hence incorrect.

CR FUNDAMENTAL -- The inference must always be drawn from the premises and it must not be dependent on the assumption.

CR Questions 35, 36

2007-02-20T16:37:00.000+08:00

35). A medical journal used a questionnaire survey to determine whether a particular change in its format would increase its readership. Sixty-two percent of those who returned the questionnaire supported that change. On the basis of this outcome, the decision was made to introduce the new format.

Which one of the following, if it were determined to be true, would provide the best evidence that the journal's decision will have the desired effect?

(A) Of the readers who received questionnires, 90 percent returned them.
(B) Other journals have based format changes on survey results.
(C) The percentage of surveyed readers who like the format change was almost the same as the percentage of the entire potential readership who would like format change.
(D) It was determined that the new format would be less costly than the old format.
(E) Ninety percent of the readers who were dissatisfied with the old format and only 50 percent of the readers who like the old format returned their questionnaires.

36). Odysseus answered well when the priests showed him a picture of those who had honored the gods and then escaped shipwreck, and asked him whether he did not now acknowledge the power of the gods—"Yes," he asked, "but where are those pictured who were drowned after their prayers?" And such is the way of all superstitions; wherein humans, having a delight in such vanities, mark the events where they are fulfilled, but where they fail, though this happens much oftener, neglect and pass them by.

Which one of the following contains the error of reasoning described by the author in the passage?

(A) I have discovered that Friday the 13th really is a day of misfortune. Just this past Friday, the 13th, I locked myself out of the house.
(B) Although Napoleon and Alexander the Great were short, Abraham Lincoln and Charles de Gaulle were tall. So short people seek leadership in order to overcome feelings of inferiority.
(C) Every semester for the past 15 years, an average of 10 percent of Ms. Elliot's history students have dropped her course before the exam. So, it seems likely that we can expect 10 percent to drop out this year.
(D) No reliable observer has ever actually seen a yeti. The strongest evidence seems to be some suspicious tracks. So I think this search for a yeti is probably a wild-goose chase.
(E) I cannot trust my lucky shirt any longer. I wore it to the game today and our team lost.

Answers --

35). OA - C

1st premise -- 90% of those who returned the questionnaire were unhappy with the old format.

2nd premise -- 50% of those who returned the questionnaire were happy with the old format.

A - incorrect - 90% of those surveyed does not mean that they subscribe to the journal

E - incorrect - Those who did not like old format could have represented only 1% of the surveyed people and those who liked it, the other 99%. Therefore, the conclusion could have been too largely biased towards those who wanted to keep the old format and thus inconclusive. Conversely, those who did not like the old format could have represented 99% of the surveyed people and those who liked it, the other 1%. In this case, the conclusion could have been too largely biased towards those who did not want to keep the old format. Therefore, E is inconclusive

A quick glance tip - Only C addresses the opinions of non-readers so only C can possibly support the conclusion

36). OA - A

We know if A => B and not B => not A (contrapositive).

The logic in the stem -- if A leads to B, then B must lead to A.
If all the people survived have prayed, then praying must be sure to make you survive. This is logically WRONG. In fact, B (praying) may or may not lead to A (survive). It is the same with choice A. Friday the thirteen may or may not leads to unlucky events even if one unlucky event happened on Friday the thirteenth.

CR Questions 33, 34

2007-02-20T16:30:00.000+08:00

33). Critic: People today place an especially high value on respect for others; yet, in their comedy acts, many of today's most popular comedians display blatant disrespect for others. But when people fail to live up to the very ideals they hold in highest esteem, exaggeration of such failings often forms the basis of successful comedy. Thus the current popularity of comedians who display disrespect in their acts is hardly surprising.

The critic's argument depends on which one of the following assumptions?

(A) People who enjoy comedians who display disrespect in their acts do not place a high value on respect for others.
(B) Only comedians who display blatant disrespect in their acts are currently successful.
(C) Many people disapprove of the portrayal of blatant disrespect for others in comedy acts.
(D) People who value an ideal especially highly do not always succeed in living up to this ideal. (E) People today fail to live up to their own ideals more frequently than was the case in the past.

34). In the course of her researches, a historian recently found two documents mentioning the same person, Erich Schnitzler. One, dated May 3, 1739, is a record of Schnitzler's arrest for peddling without a license. The second, undated, is a statement by Schnitzler asserting that he has been peddling off and on for 20 years.

The facts above best support which of the following conclusions?

(A) Schnitzler started peddling around 1719.
(B) Schnitzler was arrested repeatedly for peddling.
(C) The undated document was written before 1765.
(D) The arrest record was written after the undated document.
(E) The arrest record provides better evidence that Schnitzler peddled than does the undated document.

Answers --

33). OA - D

The passage explains the popularity of comedians: "...when people fail to live up to the very ideals they hold in highest esteem, exaggeration of such failings often forms the basis of successful comedy". So, the success of comedy is connected with the fact that COMEDIANS FAIL TO LIVE UP TO THE IDEALS THEY VALUE HIGHLY. This situation is possible only if we assume D, i.e. that there are people who fail to live up to the ideals they value highly

34). OA - C

A - If the undated document was dated 1750, then it cannot be said that Schnitzler started peddling in 1719
B - In 1739, Schnitzler could have been arrested only once
C - The most reasonable answer. If the documents were written before 1765, it would account for the fact that Schnitzler was peddling on and off for the past 20 years.
D - As stated above in C, the document could have been written in 1750. We cannot assert that it was written after the undated document.
E - Nothing supports the truthness of each document.

CR Questions 31, 32

2007-02-20T16:14:00.000+08:00

31). "If the forest continues to disappear at its present pace, the koala will approach extinction," said the biologist. "So all that is needed to save the koala is to stop deforestation," said the politician.

Which one of the following statements is consistent with the biologist's claim but not with the politician's claim?

(A) Deforestation continues and the koala becomes extinct.
(B) Deforestation is stopped and the koala becomes extinct.
(C) Reforestation begins and the koala survives.
(D) Deforestation is slowed and the koala survives.
(E) Deforestation is slowed and the koala approaches extinction

32). The postal service is badly mismanaged. Forty years ago, first-class letter delivery cost only three cents. Since then, the price has increased nearly tenfold, with an actual decrease in the speed and reliability of service.

Each of the following statements, if true, would tend to weaken the argument above EXCEPT:

(A) The volume of mail handled by the postal service has increased dramatically over the last forty years.
(B) Unprecedented increases in the cost of fuel for trucks and planes have put severe upward pressures on postal delivery costs.
(C) Private delivery services usually charge more than does the postal service for comparable delivery charges.
(D) The average delivery time for a first-class letter four decades ago was actually slightly longer than it is today.
(E) The average level of consumer prices overall has increased more than 300 percent over the last forty years.

Answers --

31). OA - B

Let A=Deforestation continues

Let B=Koala becomes extinct

If A then B

We know the only consistent true result equivalent to this is its contrapositive i.e if not B then not A.

Biologists claim -- if deforestation continues koala will definitely extinct.
Hence if deforestation stops, the koala may or may not extinct.
Politician's claim - if deforestation stops then koala will not extinct.
E -- states if deforestation is stopped koala will extinct, consistent with Biologists claim but not with the politician's claim
D is consistent with the politician's claim.
32). OA - E
Conclusion-- Postal service is mismanaged.
Argument -- The Price has increased, whereas at the same time in reality reliability and speed has decreased.
E states Inflation had increased 3 folds i.e 300 but Prices have risen 10 times..
So, the postal service is mismanaged..hence supports the argument.
D is weakening the argument from the service point of view. It states it is better now (faster).
C - incorrect - implies private services are more costly; post office services are less expensive....Hence postal services are better than private services as they are less expensive than other comparable services.

CR Questions 21 - 30

2006-10-20T14:04:00.000+08:00

21). When limitations were in effect on nuclear-arms testing, people tended to save more of their money, but when nuclear-arms testing increased, people tended to spend more of their money. The perceived threat of nuclear catastrophe, therefore, decreases the willingness of people to postpone consumption for the sake of saving money.

The argument above assumes that

A). the perceived threat of nuclear catastrophe has increased over the
years.

B). most people supported the development of nuclear arms

C). people's perception of the threat of nuclear catastrophe depends on the amount of nuclear-arms testing being done

D). the people who saved the most money when nuclear-arms testing was limited were the ones who supported such limitations

E). there are more consumer goods available when nuclear-arms testing increases

22). Which of the following best completes the passage below?
People buy prestige when they buy a premium product. They want to be associated with something special. Mass-marketing techniques and price-reduction strategies should not be used because____

A). affluent purchasers currently represent a shrinking portion of the population of all purchasers

B). continued sales depend directly on the maintenance of an aura of exclusivity

C). purchasers of premium products are concerned with the quality as well as with the price of the products

D). expansion of the market niche to include a broader spectrum of consumers will increase profits

E). manufacturing a premium brand is not necessarily more costly than manufacturing a standard brand of the same product

23). A cost-effective solution to the problem of airport congestion is to provide high-speed ground transportation between major cities lying 200 to 500 miles apart. The successful implementation of this plan would cost far less than expanding existing airports and would also reduce the number of airplanes clogging both airports and airways.

Which of the following, if true, could be proponents of the plan above most appropriately cite as a piece of evidence for the soundness of their plan?

A). An effective high-speed ground-transportation system would require major repairs to many highways and mass-transit improvements.

B). One-half of all departing flights in the nation's busiest airport head for a destination in a major city 225 miles away.

C). The majority of travelers departing from rural airports are flying to destinations in cities over 600 miles away.

D). Many new airports are being built in areas that are presently served by high-speed ground-transportation
systems.

E). A large proportion of air travelers are vacationers who are taking long-distance flights.

24). If there is an oil-supply disruption resulting in higher international oil prices, domestic oil prices in open-market countries such as the United States will rise as well, whether such countries import all or none of their oil.

If the statement in the passage concerning oil-supply disruptions is true, which of the following policies in an open-market nation is most likely to reduce the long-term economic impact on that nation of sharp and
unexpected increases in international oil prices?

A). Maintaining the quantity of oil imported at constant yearly levels

B). Increasing the number of oil tankers in its fleet

C). Suspending diplomatic relations with major oil-producing nations

D). Decreasing oil consumption through conservation

E). Decreasing domestic production of oil

25). If there is an oil-supply disruption resulting in higher international oil prices, domestic oil prices in open-market countries such as the United States will rise as well, whether such countries import all or none of their oil.

Which of the following conclusions is best supported by the statement in the passage?

A). Domestic producers of oil in open-market countries are excluded from the international oil market when there is a disruption in the international oil supply.

B). International oil-supply disruptions have little, if any, effect on the price of domestic oil as long as an open-market country has domestic supplies capable of meeting domestic demand.

C). The oil market in an open-market country is actually part of the international oil market, even if most of that country's domestic oil is usually sold to consumers within its borders.

D). Open-market countries that export little or none of their oil can maintain stable domestic oil prices even when international oil prices rise sharply.

E). If international oil prices rise, domestic distributors of oil in open-market countries will begin to import more oil than they export.

26). The average normal infant born in the United States weighs between twelve and fourteen pounds at the age of three months. Therefore, if a three-month-old child weighs only ten pounds, its weight gain has been below the United States average.

Which of the following indicates a flaw in the reasoning above?

A). Weight is only one measure of normal infant development.

B). Some three-month-old children weigh as much as seventeen pounds.

C). It is possible for a normal child to weigh ten pounds at birth.

D). The phrase "below average" does not necessarily mean insufficient.

E). Average weight gain is not the same as average weight.

27). Red blood cells in which the malarial-fever parasite resides are eliminated from a person's body after 120 days. Because the parasite cannot travel to a new generation of red blood cells, any fever that
develops in a person more than 120 days after that person has moved to a malaria-free region is not due to the malarial parasite.

Which is the following, if true, most seriously weakens the conclusion above?

A). The fever caused by the malarial parasite may resemble the fever caused by flu viruses.

B). The anopheles mosquito, which is the principal insect carrier of the malarial parasite, has been eradicated in many parts of the world.

C). Many malarial symptoms other than the fever, which can be suppressed with anti-malarial medication, can reappear within 120 days after the medication is discontinued.

D). In some cases, the parasite that causes malarial fever travels to cells of the spleen, which are less frequently eliminated from a person's body than are red blood cells.

E). In any region infested with malaria-carrying mosquitoes, there are individuals who appear to be immune to malaria.

28). Fact 1: Television advertising is becoming less effective: the proportion of brand names promoted on television that viewers of the advertising can recall is slowly decreasing.

Fact 2: Television viewers recall commercials aired first or last in a cluster of consecutive commercials far better than they recall commercials aired somewhere in the middle.

Fact 2 would be most likely to contribute to an explanation of fact 1 if which of the following were also true?

A). The average television viewer currently recalls fewer than half the brand names promoted in commercials he or she saw.

B). The total time allotted to the average cluster of consecutive television commercials is decreasing.

C). The average number of hours per day that people spend watching television is decreasing.

D). The average number of clusters of consecutive commercials per hour of television is increasing.

E). The average number of television commercials in a cluster of consecutive commercials is increasing.

29). The number of people diagnosed as having a certain intestinal disease has dropped significantly in a rural county this year, as compared to last year. Health officials attribute this decrease entirely to improved sanitary conditions at water-treatment plants, which made for cleaner water this year and thus reduced the incidence of the disease.

Which of the following, if true, would most seriously weaken the health officials' explanation for the lower incidence of the disease?

A). Many new water-treatment plants have been built in the last five years in the rural county.

B). Bottled spring water has not been consumed in significantly different quantities by people diagnosed as having the intestinal disease, as compared to people who did not contract the disease.

C). Because of a new diagnostic technique, many people who until this year would have been diagnosed as having the intestinal disease are now correctly diagnosed as suffering from intestinal ulcers.

D). Because of medical advances this year, far fewer people who contract the intestinal disease will develop severe cases of the disease.

E). The water in the rural county was brought up to the sanitary standards of the water in neighboring counties ten years ago.

30). The price the government pays for standard weapons purchased from military contractors is determined by a pricing method called "historical costing." Historical costing allows contractors to protect their profits by adding a percentage increase, based on the current rate of inflation, to the previous year's contractual price.

Which of the following statements, if true, is the best basis for a criticism of historical costing as an economically sound pricing method for military contracts?

A). The government might continue to pay for past inefficient use of funds.

B). The rate of inflation has varied considerably over the past twenty years.

C). The contractual price will be greatly affected by the cost of materials used for the products.

D). Many taxpayers question the amount of money the government spends on military contracts.

E). The pricing method based on historical costing might not encourage the development of innovative weapons.

Official answers and explanations --

21). On the basis of an observed correlation between arms testing and people’s tendency to save money, the argument concludes that there is a causal connection between a perception of threat and the tendency not to save. That connection cannot be made unless C, linking the perception of threat to the amount of testing being done, is assumed to be true. Therefore, C is the best answer.
The conclusion does not depend on there having been an increase in the perceived threat over time or on how many people supported the development of nuclear arms. Hence, neither of A and B is assumed. The argument does not deal with those who supported arms limitations or with the availability of consumer goods. Thus, D and E are not assumed.

22). The incomplete passage calls for an explanation of why price-reduction and mass-marketing methods should
not be used for premium products. B, which states that sales of these products require that they appear specials,
provides such an explanation. Therefore, B is the best answer. No other choice offers an appropriate explanation. The diminishing proportion of affluent buyers cited in A argues for using price reductions to attract buyers of lesser means. C suggests that purchasers of premium products find reduced prices attractive, and it has not been established that the methods affect quality or perception of quality. D argues for, rather than against, using mass marketing.
E is inappropriate, since there is no indication that manufacturing costs are relevant.

23). The plan proposes that high-speed ground transportation would be a less expensive solution to airport congestion than would airport expansion. B indicates that between the cities to be served by the plan there is substantial air travel to which ground transportation would represent an alternative. Therefore, B is the best answer.
No other choice could be cited appropriately. A and D both provide some evidence against the plan. A by emphasizing the likely costs of providing high-speed ground transportation is not by itself a solution to airport
congestion.
D by indicating that such an alternative is not by itself a solution to airport congestion.
C and E say that there are many travelers for whom the proposed system would actually provide no alternative.

24). If the statement about oil-supply disruption is true, domestic oil prices in an open-market country will rise when
an oil-supply disruption causes increased international oil prices. A reduction in the amount of oil an open-market country consumes could reduce the economic impact of these increases. D gives a way to reduce oil consumption and is thus the best answer.
A and E describe policies that could actually increase the long-term impact of increases in international oil prices, so neither of these choices is appropriate. No relationship is
established between the economic impact and either the number of oil tankers or diplomatic relations in B and C,
so neither of these choices is appropriate.

25). If the oil market in an open-market country were independent, fluctuations in international oil prices would not affect domestic oil prices. However, if the statement about oil-supply disruption is true, it is evidence that domestic oil prices are dependent on the international market and hence that the domestic oil market is a part of the international oil market. Therefore, C is the best answer.
B and D are not supported, since each contradicts the claim that an international oil-supply disruption will lead to rising oil prices in an open-market nation. Nor are A and E supported, since the statement provides information only about the effect of disruption on oil prices, not domestic producers or distributors.

26). The evidence on which the conclusion is based concerns only average weight, but the conclusion concerns average weight gain. Because there is not necessarily a connection between an absolute measurement-such as weight-and a rate of increase-such as weight gain-this argument is flawed. The relevant reasoning error is described in E, which is the best answer.
Neither of A and D identifies a reasoning error in the passage, since the passage makes no claim that weight is the only relevant measure of infant development in general, and no claim about sufficiency. B and C are consistent with the claims in the passage, and neither identifies a flaw in the argument.

27). The passage concludes that, because the malarial parasite cannot reside in red blood cells for more than 120
days, the malarial parasite cannot cause fever more than 120 days after infection. However, according to D, there is a site in the body where the parasite could reside for more than 120 days after infection. Therefore, D weakens the conclusion and is the best answer.
The resemblance between malarial-fever symptoms and those of other diseases, the existence of other malarial symptoms, and the possibility of immunity to malaria are irrelevant to the issue of the conditions under which malarial fever can occur. B provides confirmation for the existence of malaria-free regions but does not otherwise bear on the conclusion.

28). Because E indicates that the number of commercials in a cluster is increasing, it entails that proportionally more
commercials are aired in intermediate positions. Hence, E helps fact 2 explain fact 1 by showing that increasingly more commercials are aired in positions in which viewers find them difficult to recall. E is the best answer.
A testifies to the ineffectiveness of television advertising but does not help fact 2 explain fact 1.
B indicates that fact 2 contradicts rather than explains fact 1, since it suggests that the number of commercials per cluster is decreasing.
C and D help to explain fact 1-by describing a change in viewing habits and a change in programming-but neither relates fact 2 to fact 1.

29). The health officials’ explanation assumes that the decrease in the number of people diagnosed with the disease
accurately reflects a diminution in cases of the disease. By pointing out that this assumption is false, C undermines the officials’ explanation and thus is the best answer. Since A supports the view that sanitary conditions have been improving, it tends to support the officials’ explanation. B also tends to support the officials’ explanation, because it eliminates a factor that might have differentiated between those contracting and those not contracting the disease and thus rules out an alternative explanation. The reduction of the severity of the diagnosed cases does not bear on the officials’ explanation. So D is not correct. Since the standards in
neighboring counties might themselves have been inadequate, E does not weaken the officials’ explanation.

30). If the original contractual price for the weapons purchased incorporated an inefficient use of funds, then, since historical costing merely adds to the original price, it preserves these inefficiencies. An economically sound pricing method should at least allow the possibility of reductions in price as such inefficiencies are removed. Hence, A is the best answer. Because historical costing responds to inflation, B and C are consistent with the economic soundness of historical costing-the rate of inflation and costs that are reflected in inflation. D offers no grounds for questioning the economic soundness of historical costing in particular. Historical costing applies to standard weapons only, not to the innovative weapons that are mentioned in E.

Critical Reasoning Boldface Questions 1 - 4

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1). The survival of the publishing industry depends upon the existence of a public who will buy the printed word in the form of newspapers, books and magazines. Over the past several years, however, the advance of electronic media, particularly CD-ROMs, online computer services, and the Internet, has made 9information available to the public electronically without the need for printed materials. As the availability of electronic media increases and as it is more easily accessible, the public has less need for printed materials. So the publishing industry is threatened by the advance of the computer information age.

The two portions in boldface play which of the following roles?

(A) The first is the part of evidence that the argument includes, the second is the conclusion that can be drawn only from the first.

(B) The first is the second-premise that the argument includes; the second is the conclusion that is reasonably drawn form this passage.

(C) The first is the second-premise that the argument includes, the second is the inference that must be drawn from this argument.

(D) The first is the fact that must be true, the second is the inference that can be correctly drawn from this argument.

(E) The first is the part of premise that the argument depends on; the second is the conclusion that is incorrectly drawn from this argument

2). Gasoline-powered boat engines manufactured in the a North American country prior to 1990 contribute significantly to the pollution found in the world¡¯s oceans. In 1990, however, the government imposed stricter pollution controls on gasoline engines manufactured for boats, and beginning in 1995, the government imposed a program of inspections for pre-1990 boat engines with increasingly rigorous pollution standards. As the older boat engines fail to pass inspection, boat owners are increasingly retiring their old engines in favor of newer, less-polluting boat engines. As a result, the amount of pollution these older boat engines emit into the world's oceans will steadily decrease over the next ten years.

The two portions in boldface play which of the following roles?

(A) The first is a pattern of cause and effect that acts as an evidence in support of this argument; the second is the conclusion that can be drawn from this argument.

(B) The first is a fact that acts as a principle in support of this argument; the second is the conclusion that must be drawn from this argument.

(C) The first is a pattern of cause and effect that acts as an special evidence in support of the conclusion; the second is a general point that can be drawn from this argument.

(D) The first is a pattern of cause and effect that acts as the third evidence in support of the argument; the second is a conclusion that must be true.

(E) The first is a final evidence in support of the argument; the second is a conclusion that can be drawn only from the first.

3). The interstitial nucleus, a sub-region of the brain's hypothalamus, is typically smaller for male cats than for female cats. A neurobiologist performed autopsies on male cats who died from disease X, a disease affecting no more than 0.5 percent of male cats, and found that these male cats had interstitial nuclei that were as large as those generally found in female cats. Thus, the size of the interstitial nucleus determines whether or not male cats can contract disease X, but, the hypothalamus is known not to be causally linked to disease Y, and disease X is a subtype of disease Y.

The two portions in boldface play which of the following roles?

(A) The first is a fact in support of the consideration that is one of two points of this argument; the second is the alternative point that weighs against the first.

(B) The first is an evidence that supports the consideration that the argument includes; the second is the fact that weighs against that consideration that could be drawn from the first.

(C) The first is a general principle that is against the conclusion; the second is that conclusion.

(D) The first is an evidence that supports the conclusion; the second is an exceptional example.

(E) The first is a fact in support of the conclusion that the argument depends on; the second is a fact that is against the first one.

4). To be accepted as a member at the Brown Country Club, one must have a net worth of over ten million dollars and must not have any connections to the entertainment industry. Robert Chase, the publishing magnate, has a net worth of 5 billion dollars and chase has not financed any Hollywood movies, so he must be accepted as a member at the Brown Country Club.

The two portions in boldface play which of the following roles?

(A) The first is the part of evidence in support of this argument; the second is the conclusion that could not be drawn from all evidence that the argument contains.

(B) The first is the first-evidence that supports this argument; the second is the mainpoint that must be drawn from all evidence that the argument includes.

(C) The first is the one fact of two that argument includes; the second is the conclusion that could be drawn from this passage.

(D) The first is the background that is necessary for this argument; the second is the conclusion that is not drawn only from the first.

(E) The first is the cause that the argument includes; the second is the effect that can be drawn only from this cause.

Answers --

1). The correct answer is D.
The first portion of BF is a fact --- Over the past several years …
Evidence --- As the availability of electronic...….. printed materials"Conclusion --- So the publishing industry……. the computer information age
A, B, C, E – incorrect -- the first statement is considered as premise. Further the use of “only” in choice A also makes it incorrect.

2). The correct answer choice is A.
The 1st BF is a premise showing 'cause and effect' relationship --- As the older boat….boat engines
The 2nd BF is the conclusion --- the amount of pollution…..next en years.Fact --- the government imposed stricter pollution ……
B – incorrect – 1st BF is not a fact. Use of MUST incorrect too.
C – incorrect – 1st BF is not special evidence, and 2nd BF is a conclusion instead of just being a general point.
D – incorrect – use of MUST makes it incorrect as extrem tones are not generally entertained in GMAT. Also the 1st Bf is not the 3rd evidence but is followed from a series of cause and effects sted before.
E – incorrect – the 1st is not the final evidence. Further the use of “only” makes this choice incorrect.

3). The correct answer choice is A.
Conclusion --- "thus the size of interstitial...contract disease X"
B – incorrect -- from the second you cannot draw the first. 2nd statement is combination of two facts. From these two facts you can conclude that -- hypothalamus is not directly related to disease X
So not fact itself but conclusion derived from these facts weighs against that consideration
C – incorrect -- conclusion is "thus the size of interstitial...contract disease X" and not the 2nd.
D – incorrect -- 2nd is general and not exceptional.
E – incorrect -- 1st and 2nd are not contradictory to each other.

4). The correct answer choice is A.
1st BF portion is part of evidence --- Robert Chase, the publishing magnate…. Hollywood movies --- it tells that Chase has more than 10 million dollars, but it also states that Chase has not financed any Hollywood movies. Not financing hollywood movies does not imply that he does not finances any other entertainment businesses too.
2nd BF portion is the conclusion --- he must be accepted ….. Brown Country Club.
There are 2 conditions which must be fulfilled in order to be accepted as a member of Brown Country Club, firstly – should have over 10 million dollars and secondly -- should not have any connections to the entertainment industry -- the two required conditions are not fulfilled, thus the conclusion that cannot be drawn from the evidences stated in the first part.
B – incorrect – use of MUST incorrect.
C – incorrect – the conclusion cannot be drawn from this passage.
D – incorrect – the statement preceding the 1st BF is the background.
E – incorrect – use of “only” makes this choice incorrect.

How to approach Boldface Question in Critical Reasoning !

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Firstly BF CR (Bold face Critical reasoning) questions lie in tough category -- so if you come across one - will imply that you are doing extremely well in GMAT

In BF CR argument question, one or two different statements in stimulus appear in BOLD. The question then asks you the way in which the two statements in bold are related?

Few basic terms that form the parts of an argument --

1). Argument

An argument is a conclusion supported by premises and assumptions. It has 3 parts: Conclusion, Premise and Assumption.

2). Conclusion

A conclusion is a claim, the main point of an argument. Certain words are used to introduce the conclusion of an argument, these words are termed as Conclusion Indicators e.g -- so, thus, therefore, as a result, consequently, accordingly, hence,imply, conclude that, follows that, means that, infer that

3). Premises

Premises are parts of argument that support the conclusion.They are the reasons that back up the claim made in the conclusion. Most of the time premises are facts, but they can also be assertions that are just given as evidence for the claim in the conclusion. A conclusion gets support:premises provide it. In simple words a premise is a stated reason, a piece of evidence that supports the conclusion. Premises are the argument's facts.They are the facts or evidence that support or lead to the conclusion.
Certain words are used to introduce the premises of an argument, these words are termed as Premise Indicators. e.g – because, since, for, as, if, assume, suppose, evidence, on the basis of, the reason is that, may be derived from, in that

4). Assumption

An assumption is an unstated premise that supports the conclusion. It is something that the author’s conclusion “depends on” or “relies on”.

5). Inference

We can infer many details from the arguments. Inferences are those details, which are known to be true from information presented. Sometimes there is no difference between a conclusion and an inference. When the conclusion to an argument is not explicitely stated, it is something you can infer. In other words, inferences have nothing to do with the main point of an argument. You can infer inferences from the facts that are stated as premises.

6). Background

Information or circumstances required to put the evidence into context but which, on standing alone as pieces of information, might not constitute an evidence that is necessary to arrive at a conclusion. It doesn't states anything directly, just provides the general information related to the topic...

7). Pre-evidence in almost same as background.. .

8). Evidence

Information indicating whether something is true or valid. It is something that supports the argument, or tries to prove it's validity .
Evidence may include facts, but an evidence is usually stronger than a fact. The evidence are the direct elements required for the conclusion to stand whereas facts are not necessary for the conclusion to stand.

9). Fact

Something that is definitely the case. It is the information used as evidence.

10). Consideration

Something which was taken into account or given careful thought before arriving to the conclusion or while making a decision.

11). Principle

Something that is broad and basic rule or truth / fundamental that is not put to question. A principle can be stronger than a fact because it is not specific to a limited number of cases but instead, apply to a broader range of scenarios(and often deeper in meaning).

12). Counter premise/Evidence

While an author always wants to present a strong case, he may concede minor points that weaken his argument to show that he is open-minded and that his ideas are well-considered.These points are termed as counter premises.
This technique also disarms potential arguments against his position.
Counter-evidence Indicators -- actually, despite, admittedly, except, even though, nonetheless, nevertheless, although, however, In spite of, do, may

How to approach Boldface Question -

1).Read carefully the set of statements on which the question is based.

2). Identify the conclusion. Be alert to clues in the text i.e Conclusion Indicators e.g -- so, thus, therefore, as a result, consequently, accordingly, hence,imply, conclude that, follows that, means that, infer that.

3). Pay attention to the evidence that the author uses to support/ argue against a position.

4). Look out for for various argument indicators to analyse and determine the relationship between evidence and conclusion. e.g Premise indicators, Counter premise indicators, Conclusion indicators etc.

Note – Do not mistake evidence for counter evidence.

CR Questions 11 - 20

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Questions 11-12 are based on the following.

To protect certain fledgling industries, the government of country Z banned imports of the types of products those industries were starting to make. As a direct result, the cost of those products to the buyers, several export-dependent industries in Z, went up, sharply limiting the ability of those industries to compete effectively in their export markets.

11. Which of the following can be most properly inferred from the passage about the products whose importation was banned?

(A) Those products had been cheaper to import than they were to make within country Z’s fledgling industries.

(B) Those products were ones that country Z was hoping to export in its turn, once the fledgling industries matured.

(C) Those products used to be imported from just those countries to which country Z’s exports went.

(D) Those products had become more and more expensive to import, which resulted in a foreign trade deficit just before the ban.

(E) Those products used to be imported in very small quantities, but they were essential to country Z’s economy.

12. Which of the following conclusions about country Z’s adversely affected export-dependent industries is best supported by the passage?

(A) Profit margins in those industries were not high enough to absorb the rise in costs mentioned above.

(B) Those industries had to contend with the fact that other countries banned imports from country Z.

(C) Those industries succeeded in expanding the domestic market for their products.

(D) Steps to offset rising materials costs by decreasing labor costs were taken in those industries.

(E) Those industries started to move into export markets that they had previously judged unprofitable.

13. The difficulty with the proposed high-speed train line is that a used plane can be bought for one-third the price of the train line, and the plane, which is just as fast, can fly anywhere. The train would be a fixed linear system, and we live in a world that is spreading out in all directions and in which consumers choose the free-wheel systems (cars, buses, aircraft), which do not have fixed routes. Thus a sufficient market for the train will not exist.

Which of the following, if true, most seriously weakens the argument presented above?

(A) Cars, buses, and planes require the efforts of drivers and pilots to guide them, whereas the train will be guided mechanically.

(B) Cars and buses are not nearly as fast as the high-speed train will be.

(C) Planes are not a free-wheel system because they can fly upon between airports, which are less convenient for consumers than the high speed train’s stations would be.

(D) The high-speed train line cannot use currently underutilized train stations in large cities.

(E) For long trips, most people prefer to fly rather than to take ground level transportation.

14. Correctly measuring the productivity of service workers is complex. Consider, for example, postal workers: they are often said to be more productive if more letters are delivered per postal worker. But is this really true? what if more letters are lost or delayed per worker at the same time that more are delivered?

The objection implied above to the productivity measure described is based on doubts about the truth of which of the following statements?

(A) Postal workers are representative of service workers in general.

(B) The delivery of letters is the primary activity of the postal service.

(C) Productivity should be ascribed to categories of workers, not to individuals.

(D) The quality of services rendered can appropriately be ignored in computing productivity.

(E) The number of letters delivered is relevant to measuring the productivity of postal workers.

15. Male bowerbirds construct elaborately decorated nests, or bowers. Basing their judgment on the fact that different local populations of bowerbirds of the same species build bowers that exhibit different building and decorative styles, researchers have concluded that the bowerbirds’ building styles are a culturally acquired, rather than a genetically transmitted, trait.

Which of the following, if true, would most strengthen the conclusion drawn by the researchers?

(A) There are more common characteristics than there are differences among the bower-building styles of the local bowerbird population that has been studied most extensively

(B) Young male bowerbirds are inept at bower-building and apparently spend years watching their elders before becoming accomplished in the local bower style.

(C) The bowers of one species of bowerbird lack the towers and ornamentation characteristic of the bowers of most other species of bowerbird.

(D) Bowerbirds are found only in New Guinea and Australia, where local populations of the birds apparently seldom have contact with one another.

(E) It is well known that the song dialects of some songbirds are learned rather than transmitted genetically.

16. A greater number of newspapers are sold in Town S than in Town T. Therefore, the citizens of Town S are better informed about major world events than are the citizens of Town T.

Each of the following, if true, weakens the conclusion above EXCEPT:

(A) Town S has a larger population than Town T.

(B) Most citizens of Town T work in Town S and buy their newspapers there.

(C) The average citizen of Town S spends less time reading newspapers than does the average citizen of Town T.

(D) A weekly newspaper restricted to the coverage of local events is published in Town S.

(E) The average newsstand price of newspapers sold in Town S in lower than the average price of newspapers sold in Town T.

17. A drug that is highly effective in treating many types of infection can, at present, be obtained only from the bark of the ibora, a tree that is quite rare in the wild. It takes the bark of 5,000 tree to make one kilogram of the drug. It follows, therefore, that continued production of the drug must inevitably lead to the ibora’s extinction.

Which of the following, if true, most seriously weakens the argument above?

(A) The drug made from ibora bark is dispensed to doctors from a central authority.

(B) The drug made from ibora bark is expensive to produce.

(C) The leaves of the ibora are used in a number of medical products.

(D) The ibora can be propagated from cuttings and grown under cultivation.

(E) The ibora generally grows in largely inaccessible places.

18. High levels of fertilizer and pesticides, needed when farmers try to produce high yield of the same crop year after year, pollute water supplies. Experts therefore urge farmers to diversify their crops and to rotate their plantings yearly. To receive governmental price-support benefits for a crop, farmers must have produced that same crop for the past several years.

The statements above, if true, best support which of the following conclusions?

(A) The rules for governmental support of farm prices work against efforts to reduce water pollution.

(B) The only solution to the problem of water pollution from fertilizers and pesticides is to take farmland out of production.

(C) Farmers can continue to make a profit by rotating diverse crops, thus reducing costs for chemicals, but not by planting the same crop each year.

(D) New farming techniques will be developed to make it possible for farmers to reduce the application of fertilizers and pesticides.

(E) Governmental price supports for farm products are set at levels that are not high enough to allow farmers to get out of debt.

19. Shelby Industries manufactures and sells the same gauges as Jones Industries. Employee wages account for forty percent of the cost of manufacturing gauges at both Shelby Industries and Jones Industries. Shelby Industries is seeking a competitive advantage over Jones Industries. Therefore, to promote this end, Shelby Industries should lower employee wages.

Which of the following, if true, would most weaken the argument above?

(A) Because they make a small number of precision instruments, gauge manufacturers cannot receive volume discounts on raw materials.

(B) Lowering wages would reduce the quality of employee work, and this reduced quality would lead to lowered sales.

(C) Jones Industries has taken away twenty percent of Shelby Industries’ business over the last year.

(D) Shelby Industries pays its employees, on average, ten percent more than does Jones Industries.

(E) Many people who work for manufacturing plants live in areas in which the manufacturing plant they work for is the only industry.

20. . Some communities in Florida are populated almost exclusively by retired people and contain few, if any, families with small children. Yet these communities are home to thriving businesses specializing in the rental of furniture for infants and small children.

Which of the following, if true, best reconciles the seeming discrepancy described above?

(A) The businesses specializing in the rental of children’s furniture buy their furniture from distributors outside of Florida.

(B) The few children who do reside in these communities all know each other and often make overnight visits to one another’s houses.

(C) Many residents of these communities who move frequently prefer renting their furniture to buying it outright.

(D) Many residents of these communities must provide for the needs of visiting grandchildren several weeks a year.

(E) Children’s furniture available for rental is of the same quality as that available for sale in the stores.

Official answers and explanation --

11. In Z, when the government banned imports of certain products the cost of those produces rose, so the products
must have been cheaper to import than they were to make in Z. Therefore choice A is the best answer.
None of the other choices can be inferred. Country Z need have had no plan to export those products later (choice B), nor need the products have come previously from those countries to which country Z exported goods (choice C). The products need not have become more expensive before the ban (choice D), and they could have been imported in relatively large quantities (choice E).

12. When the cost of the products rose, the competitive ability of those export-dependent industries that bought them was sharply limited. This fact strongly supports the claim that those industries did not have sufficiently high profit margins to enable them to absorb the price increase, so choice A is the best answer.
Given the limitation on their competitive ability, it is unlikely that those industries would be able either to expand
their domestic markets (choice C) or to enter into new export markets (choice E). The other choices relate
situations that would be possible but that are not strongly supported: other countries could have continued to
permit imports from Z (choice B), and the industries may have unable to decrease labor costs (choice D).

13. The author argues that planes, since they are a free-wheel system, will be preferred to the high-speed train. Choice C weakens the argument by pointing out that planes are not a free-wheel system and are les convenient than the high-speed train would be. Thus C is the best answer.
The special feature of the high-speed train described in A is not one that clearly affects consumer choice one way or the other way. Since it is planes that would compete effectively with the proposed trains, the fact that cars and buses might not do so is irrelevant. Non-availability of certain station (choice D) and the consumer preferences described in choice E tend to make the proposed train less, not more, attractive and so both choices strengthen the argument.

14. The critique of the proposed purely quantitative measure of productivity raises the issue of quality of service, which implies that quality of service is a potentially relevant consideration. Thus, choice D is the best answer.
The objection assumes that postal workers are a suitable illustrative example of service workers in general; thus,
choice A is inappropriate. By delivery of letters, the argument treats letter delivery as the primary activity of
postal workers; thus, choice B is inappropriate. Because the passage explicitly ascribes productivity to entire
categories of workers, choice C is inappropriate. Choice E is inappropriate, since the objector does not question
the relevance of the number of letters delivered but implies that something else might also be relevant.

15. The information in choice B says that young bowerbirds progress slowly toward mastery of a bower-building
style, which suggests that the skill is one they must learn, rather than one whose transmission is wholly genetic.
Choice B also suggests a means of cultural transmission, namely, observation of older birds’ technique. Thus, B
supports the conclusion and is the best answer.
That differences within building styles are outnumbered by similarities (choice A) and that local populations have
little contact (choice D) are both equally consistent with building-style differences being culturally acquired or
genetically transmitted. Nor are differences among species of bowerbird (choice C) the issue. Finally, choice E
confirms the possibility of birds leaning skills, but it is not evidence that bower-building styles are learned.

16. The conclusion is based on comparing newspaper sales in Town S and Town T. Four answer choices indicate
why greater newspaper sales in S need not imply that citizens of S are better informed about world events.
Choice B suggests that many newspapers sold in S inform citizens of T, not S. Choices A and C both show how
greater newspaper sales can occur without the average citizen having greater familiarity with the news. Finally,
choice D suggests that much newspaper reading in S is not a source of information about world events. The price differential noted in E might help to explain the difference in sales, but it does not undermine the conclusion based on that difference. Therefore, E is the best answer.

17. If the ibora can be successfully cultivated, it is possible to continue production of the drug without threatening the
ibora with extinction. Therefore, choice D is the best answer.
If production continues, the method for distributing the drug aftr it has been produced (choice A) is not likely, on its own, to have consequences for the continued existence of the ibora. Nor is the price of the drug (choice B). If the leaves of the ibora also have a use (choice C), the threat of extinction is strengthened rather than weakened. Finally, if the ibora is largely inaccessible (choice E), this bears on the question of whether production of the drug could continue, not on what would happen if it did continue.

18. Farmers benefit from governmental price supports only when they produce the same crops from year to year. Farmers who wish to receive the benefit of these price supports will be unlikely to reduce water pollution
because they will not follow the experts’ advice regarding diversification and rotation. Thus, A is the best answer.
Since the experts’ advice is evidently their favored solution, the notion that the sole solution is something else (choice B) is not supported. The statements mention neither farmers' costs and revenues nor development in farming techniques, and thus support no conclusions about prospects for profits (choice C) or future farming techniques (choice D). Because no information is given about either the amount of price support or farmers debt, choice E is not supported.

19. According to choice B, the effect of lowering wages is to reduce quality sufficiently to reduce sales. This is a good reason to doubt that wage cuts would give Shelby Industries any competitive advantage, so choice B is the
best answer.
Some of the other choices provide good reasons for, rather than against, lowering wages. Choice A implies that
reducing the cost of raw materials is not possible, choice D indicates that Shelby Industries’ wages are relatively
high, and choice E suggests that Shelby Industries would not lose many workers if it did reduce wages. Choice
C gives a reason for Shelby Industries to be concerned about its competitive position but no reason to think
wage cuts would not improve that position.

20. If many residents of these communities host visiting grandchildren several weeks a year, as D states, that in
itself might generate sufficient demand for rented children’s furniture to support thriving businesses. Thus, D
helps reconcile the apparent discrepancy and is the best answer.
The few households mentioned in choice B are unlikely to generate sufficient demand for rental businesses to
thrive. Similarly, choices A and E, though they provide information concerning the furniture that is rented in these communities, do not address the prior issue of why there should be such demand for children's furniture. Choice C helps explain why these communities have an unusually high demand for rental furniture, but not why such a demand would extend to children's furniture.

CR Questions 1 - 10

2006-10-07T22:39:00.000+08:00

1. Many institutions of higher education suffer declining enrollments during periods of economic slowdown. At two-year community colleges, however, enrollment figures boom during these periods when many people have less money and there is more competition for jobs.

Each of the following, if true, helps to explain the enrollment increases in two-year community colleges described above EXCEPT:

(A) During periods of economic slowdown, two-year community colleges are more likely than four-year colleges to prepare their students for the jobs that are still available.

(B) During periods of economic prosperity, graduates of two-year community colleges often continue their studies at four-year colleges.

(C) Tuition at most two-year community colleges is a fraction of that at four-year colleges.

(D) Two-year community colleges devote more resources than do other colleges to attracting those students especially affected by economic slowdowns.

(E) Students at two-year community colleges, but not those at most four-year colleges, can control the cost of their studies by choosing the number of courses they take each term.

Question 2-3 are based on the following

Hardin argued that grazing land held in common (that is, open to any user) would always be used less carefully than private grazing land. Each rancher would be tempted to overuse common land because the benefits would accrue to the individual, while the costs of reduced land quality that results from overuse would be spread among all users. But a study comparing 217 million acres of common grazing land with 433 million acres of private grazing land showed that the common land was in better condition.

2. The answer to which of the following questions would be most useful in evaluating the significance, in relation to Hardin’s claim, of the study described above?

(A) Did any of the ranchers whose land was studied use both common and private land?

(B) Did the ranchers whose land was studied tend to prefer using common land over using private land for grazing?

(C) Was the private land that was studied of comparable quality to the common land before either was used for grazing?

(D) Were the users of the common land that was studied at least as prosperous as the users of the private land?

(E) Were there any owners of herds who used only common land, and no private land, for grazing?

3. Which of the following, if true and known by the ranchers, would best help explain the results of the study?

(A) With private grazing land, both the costs and the benefits of overuse fall to the individual user.

(B) The cost in reduced land quality that is attributable to any individual user is less easily measured with common land than it is with private land.

(C) An individual who overuses common grazing land might be able to achieve higher returns than other users can, with the result that he or she would obtain a competitive advantage.

(D) If one user of common land overuses it even slightly, the other users are likely to do so even more, with the consequence that the costs to each user outweigh the benefits.

(E)There are more acres of grazing land held privately than there are held in common.

4. In tests for pironoma, a serious disease, a false positive result indicates that people have pironoma when, in fact, they do not; a false negative result indicates that people do not have pironoma when, in fact, they do. To detect pironoma most accurately, physicians should use the laboratory test that has the lowest proportion of false positive results.

Which of the following, if true, gives the most support to the recommendation above?

(A) The accepted treatment for pironoma does not have damaging side effects.

(B) The laboratory test that has the lowest proportion of false positive results causes the same minor side effects as do the other laboratory tests used to detect pironoma.

(C) In treating pironoma patients, it is essential to begin treatment as early as possible, since even a week of delay can result in loss of life.

(D) The proportion of inconclusive test results is equal for all laboratory tests used to detect pironoma.

(E) All laboratory tests to detect pironoma have the same proportion of false negative results.

Questions 5-6 are based on the following.

In many corporations, employees are being replaced by automated equipment in order to save money. However,many workers who lose their jobs to automation will need government assistance to survive, and the same corporations that are laying people off will eventually pay for that assistance through increased taxes and unemployment insurance payments.

5. The author is arguing that

(A) higher taxes and unemployment insurance payments will discourage corporations from automating

(B) replacing people through automation to reduce production costs will result in increases of other costs to corporations.

(C) many workers who lose their jobs to automation will have to be retrained for new jobs

(D) corporations that are laying people off will eventually rehire many of them

(E) corporations will not save money by automating because people will be needed to run the new machines

6.Which of the following, if true, most strengthens the author's argument?

(A) Many workers who have already lost their jobs to automation have been unable to find new jobs.

(B) Many corporations that have failed to automate have seen their profits decline.

(C) Taxes and unemployment insurance are paid also by corporations that are not automating.

(D) Most of the new jobs created by automation pay less than the jobs eliminated by automation did.

(E) The initial investment in machinery for automation is often greater than the short-term savings in labor costs.

7. The sustained massive use of pesticides in farming has two effects that are especially pernicious. First, it often kills off the pests' natural enemies in the area. Second, it often unintentionally gives rise to insecticide-resistant pests, since those insects that survive a particular insecticide will be the ones most resistant to it, and they are the ones left to breed.

From the passage above, it can be properly inferred that the effectiveness of the sustained massive use of pesticides can be extended by doing which of the following, assuming that each is a realistic possibility?

(A) Using only chemically stable insecticides

(B) Periodically switching the type of insecticide used

(C) Gradually increasing the quantities of pesticides used

(D) Leaving a few fields fallow every year

(E) Breeding higher-yielding varieties of crop plants

8. When a polygraph test is judged inconclusive, this is no reflection on the examinee. Rather, such a judgment means that the test has failed to show whether the examinee was truthful or untruthful. Nevertheless, employers will sometimes refuse to hire a job applicant because of an inconclusive polygraph test result.

Which of the following conclusions can most properly be drawn from the information above?

(A) Most examinees with inconclusive polygraph test results are in fact untruthful.

(B) Polygraph tests should not be used by employers in the consideration of job applicants.

(C) An inconclusive polygraph test result is sometimes unfairly held against the examinee.

(D) A polygraph test indicating that an examinee is untruthful can sometimes be mistaken.

(E) Some employers have refused to consider the results of polygraph tests when evaluating job applicants.

9. According to the new office smoking regulations, only employees who have enclosed office may smoke at their desks. Virtually all employees with enclosed offices are at the professional level, and virtually all secretarial employees lack enclosed offices. Therefore, secretaries who smoke should be offered enclosed offices.

Which of the following is an assumption that enables the conclusion above to be properly drawn?

(A) Employees at the professional level who do not smoke should keep their enclosed offices.

(B) Employees with enclosed offices should not smoke at their desks, even though the new regulations permit them to do so.

(C) Employees at the secretarial level should be allowed to smoke at their desks, even if they do not have enclosed offices.

(D) The smoking regulations should allow all employees who smoke an equal opportunity to do so, regardless of an employee’s job level.

(E) The smoking regulations should provide equal protection from any hazards associated with smoking to all employees who do not smoke.

10. Dental researchers recently discovered that tooth-brushes can become contaminated wth bacterial that cause pneumonia and strep throat. They found that contamination usually occurs after toothbrushes have been used for four weeks. For that reason, people should replace their toothbrushes at least once a month.

Which of the following, if true, would most weaken the conclusion above?
(A) The dental researchers could not discover why toothbrush contamination usually occurred only after toothbrushes had been used for four weeks.

(B) The dental researchers failed to investigate contamination of toothbrushes by viruses, yeasts, and other pathogenic microorganisms.

(C) The dental researchers found that among people who used toothbrushes contaminated with bacterial that cause pneumonia and strep throat, the incidence of these diseases was no higher than among people who used uncontaminated toothbrushes.

(D) The dental researchers found that people who rinsed their toothbrushes thoroughly in hot water after each use were as likely to have contaminated toothbrushes as were people who only rinsed their toothbrushes hurriedly in cold water after each use.

(E) The dental researchers found that, after six weeks of use, greater length of use of a toothbrush did not correlate with a higher number of bacterial being present.

Official answers and official explanations..

1. Choice B, the best answer, might explain the decreased enrollment at four-year colleges during the slowdown,but because it deals with graduates of two-year colleges it cannot explain why enrollment at these colleges might increase
Four of the choices give reasons why, in an economic showdown, many people would choose a two-year college.
Choice A indicates that a two-year college education gives one a better chance of finding a job when economic conditions are poor.
Choice C and E indicate why people with less money might prefer two-year colleges.
Choice D suggests that more is being done to attract people whose lives are affected by the slowdown to two-year than to four-year colleges.

2. Hardin’s claim is that common grazing land deteriorates more quickly than private grazing land because of overuse. The study indicates that common grazing land is currently in better shape, but this would not
undermine Hardin’s claim if common grazing land was in far better shape before grazing began. Thus, choice C is the best answer.
Choices A and E are inappropriate since the study can undermine Hardin’s Claim whether or not some ranchers use both sorts of land, or use only common land.
Similarly, the study can undermine Hardin’s claim whether or not ranchers prefer to use common land, as B says.
Finally, D is inappropriate since the force of the study is not
diminished if users of common land are more or less prosperous.

3. The study indicates that common lands are in better shape than private lands. The best answer, D, indicates that,
contrary to Hardin’s claim, it is in each rancher’s self-interest not to overuse common land, which would explain why common lands are in relatively good shape.
Choices A and C can only explain why private land is in better shape than common land, not the reverse.
Neither the fact that it is more difficult to attribute deterioration of common land to any particular user (choice B) nor the
fact that the relative amounts of common and private land differ (choice E) gives a reason for farmers not to graze their herds on common land as much as possible.

4. The most accurate test for pironoma would be the one with the fewest false results. If all tests have the same proportion of false negatives, then the most accurate is the one that has the lowest proportion of false positives. Thus, E supports the recommendation and is the best answer.
Choice A and C deal with the treatment for pironoma and are irrelevant to the accuracy of tests pironoma.
Choice B deals with the side effects of tests for pironoma, and does not address their accuracy.
That the proportion of inconclusive test results is equal for all tests (choice D) leaves open the question of which test is
more accurate, since it does not indicate which test has fewest false results.

5. The author argues that replacing employees with automated equipment might lend to less savings for corporations than anticipated, since laying off workers will lead to other costs. Choice B states the author’s main points and thus is the best answer.
The author argues that corporations that automate might incur unexpected costs, but the author does not argue that these costs will discourage corporations from automating (choice A).
The author does not address the issues of retraining (choice C) and rehiring (choice D).
Although the author argues that some unanticipated costs might offsets savings resulting from automation, the cost of running the new machines (choice E) is clearly not one of these unanticipated costs.

6. The threat envisioned by the author to the economic survival of workers displaced by automation will be serious only if they cannot find new jobs. Choice A, the best answer, says that there are already many such workers unable to find new jobs, and so strengthens the author’s argument.
Since the causes for declining profits for corporations that fail to automate are not analyzed in the passage, B is
inappropriate.
By saying that costs associated with unemployment C weakens the argument.
Since the author
tacitly grants that, initially, automation will cut costs, the detail given in D provides us added support.
Choice E is
inappropriate because it concerns short-term rather than long-term results of automation.

7. Choice B gives a way of counteracting a serious drawback of the sustained massive use of pesticides. By periodically changing the pesticide used, pests resistant to one pesticide might be killed by the next pesticide, and those resistant to that pesticide might be killed by another, and so. Therefore, B is the best answer.
Choice A is inappropriate, since the effects of stable pesticides would simply be more persistent.
Gradually increasing pesticide amounts (choice C) will likely have no effect on pests already resistant to massive amounts.
Leaving a few fields fallow (choice D) is not relevant to the effectiveness of sustained use of pesticides.
Breeding higher-yielding crops (choice E) might temporarily increase yields, but not because of anything to do with pesticides.

8. The passage indicates that an inconclusive polygraph test tells nothing about the person who has taken the test, and yet employers sometimes refuse to hire someone whose results from such a test are inclusive. Treating lack of information as if it were unfavorable evidence about a person can reasonably be considered unfair. There, C is the best choice.
Choice A is not supported, since the passage says that an inconclusive polygraph test is no reflection on the examinee.
Neither B nor D is supported, since the information given includes nothing either implicit or explicit about polygraph tests that yield conclusive results.
Since the passage is consistent with both E and its denial, E is not supported.

9. The regulations allow some employees-those with enclosed offices-but not others the opportunity to smoke at their desks. If it is assumed that the regulations should allow all employees equal opportunity to smoke, those who are currently denied this opportunity should be given it, and so secretaries who smoke should be offered enclosed offices. Therefore, choice D is the best answer.
None of the other choices enables the conclusion to be properly drawn. Choice A tends to conflict with the conclusion, unless some enclosed offices are vacant.
Choice B supports no conclusion about how secretaries should be treated, Choice C undermines the conclusion.
Finally, nonsmokers already have equal protection from hazards, so choice E cannot be used to justify making any changes.

10. According to choice C, using a contaminated toothbrush does not increase the incidence of infection, so the recommendation to replace a toothbrush before it becomes contaminated is greatly undermined. Choice C is therefore the best answer.
Since the recommendation is based on the discovery that bacterial contamination occurs after about four weeks, the researchers’ inability to discover why contamination takes that long to appear does not weaken the recommendation (choice A), nor does their failure to investigate other forms of contamination (choice B), nor does the discovery that contamination does not worsen after six weeks (choice E). According to choice D, even thorough washing cannot prevent contamination, so replacing the toothbrush appears more essential, rather than less so.

Critical Reasoning - Approach

2006-09-29T13:52:00.000+08:00

GMAT VERBAL SECTION - CRITICAL REASONING AND ANALYSIS OF AN ARGUMENT

Logistics of the Arguments Section

The arguments comprise one-third of the Verbal section of the GMAT i.e approximately 14 questions.

What is an Argument ?

An argument is an attempt to provide a reason for believing something by citing something else.No of claims are put forward in an argument,the claim that is being supported is the conclusion.Claims alleged to support the conclusion are the premises.

Words ,Phrases supporting Conclusions:

So;
This shows that;
Therefore;
We can infer that;
Hence;
Consequently;
It follows that;
This indicates that;
For that reason,we may say;

Words ,Phrases introducing Premises:

The reason is that;
Because;
Since;
Evidence;
On the basis of;
t follows from;
In view of;
We may infer from;

Gap between Premises and Conclusions is Assumptions—identify the gaps and use it to find the solution.

Classification of Arguments

Deductive arguments are those in which the conclusion necessarily follows from the premises/evidence. It shows tight connection between the Premises and Conclusions. Most arguments on the test are inductive, where the author presents the evidence as support for the conclusion. The validity of the conclusion depends on the strength of the evidence.

Unlike deductive arguments, the conclusion of an inductive argument is always uncertain. You must be prepared to handle both reasonable arguments (when the conclusion is likely) and false arguments (when the conclusion is improbable). Each classification of inductive reasoning carries its own associated fallacies.

Evaluation of an Argument—To find errors in Arguments

(1) If-Then Statements

Most arguments are based on some variation of an if-then statement, which may be either directly stated or embedded. Understanding the if-then premise reveals the underlying simplicity of arguments.

If the premise of an if-then statement is true, then the conclusion must be true as well.

If A, then B

While three possible statements can be derived from the implication "if A, then B", only one is valid.

The statement that IS logically equivalent to "if A, then B" is called the contrapositive. It is stated as:

If not B, then not A

Let's explore why this is true.

"If there is a hurricane, then Samantha will cry"

There are four different hypothetical possibilities to consider when making deductions based on this statement:

1) A hurricane occurs
2) A hurricane does not occur
3) Samantha cries
4) Samantha does not cry

Let's consider each individually:

1. If a hurricane occurs.

You know that if this is true, the result will be that Samantha will cry.

2. If a hurricane does not occur.

If a hurricane does not occur, you can deduce nothing about Samantha. In particular, you cannot deduce that she does not cry. There are many other reasons why Samantha could cry, besides a hurricane (fight with her mom, she sees a sad movie, she gets sick).

3. If Samantha cries.

Again, you can't deduce anything about the occurence of a hurricane if Samantha cries. The if-then statement doesn't assert that Samantha cries only if a hurricane occurs, just that if it does, Samantha will cry. Samantha can cry even on clear, sunny days.

4. If Samantha does not cry.

If Samantha does not cry, you can deduce that a hurricane did not occur. Why? If it had occurred, then Samantha would definitely have cried. Yet she didn't. So, we know that, given Samantha's disposition, a hurricane did not occur.

To review, any time you see a statement in the form of "If A, then B", contrapose the statement into "If not B, then not A".

You know only two things:

a) what will happen if X occurs
b) what will happen if Y does not occur.

Those are the only valid deductions that you can make based on that original statement.

You can only assume two things about the implication "if A, then B":

1) If A is true, then B must be true.
2) If B is false, then A must be false.

2) Embedded If-Then Statements

If-then statements are frequently embedded in other structures, making their detection more difficult.

Example: (Embedded If-then)

Jamie and Kyle cannot both go to the mall.

At first glance, this sentence does not appear to contain an if-then statement. But it essentially says:

"if Jamie goes to the mall, then Kyle does not."

The contrapositive ("if Kyle goes to the mall, then Jamie does not") correctly expresses the same thing.

Example: (Embedded If-then)

Heather will go to Europe only if she gets a raise at work.

Given this statement, we know that if Heather goes to Europe, she must have gotten a raise at work.Students often wrongly interpret this statement to mean:

"If Heather gets a raise at work, then she will go to Europe."

We have no guarantee of this. The only guarantee is that if Heather doesn't get the raise, she will not go to Europe.

"A only if B" is logically equivalent to "if A, then B"

Fallacies from no.3 to no.15 are not important for Critical reasoning Questions but a student should know about them

3) Circular Reasoning

Here an unsubstantiated assertion is used to justify another unsubstantiated assertion,which is,or atleast could be ,used to justify the first statement.For instance,

Full scholarships are appropriate for disadantaged scholars because it is right to offer a top-notch education to those most capable.

This argument is circular because "right" means essentially the same thing as "appropriate." In effect, the author writer is saying that scholarships are appropriate because they are appropriate.

(4) The Biased Sample Fallacy

This is commited whenever the data for a statistical inference is drawn from a sample that is not representative of the population under consideration.

For example:

In a recent survey conducted by The Times of India of its readers,60% of the respondents indicated strong support to Lalu Prasad Yadav.Hence the survey clearly shows that Lalu yadav is the most popular leader among the masses.

The data for the inference in this argument is drawn from a sample that is not reprentative of the entire electorate.

6) The Insufficient Sample Fallacy

The Fallacy of the Insufficient Sample is committed whenever an inadequate sample is used to justify the conclusion drawn.
Here's an argument that commits the fallacy of the insufficient sample:

I have worked with three people from Bangalore City and found them to be obnoxious, pushy and rude. It is obvious that people from Bangalore City have a bad attitude.

The data for the inference in this argument is insufficient to support the conclusion. Three observations of people are not sufficient to support a conclusion for whole city population..

(4) Ad hominem

One of the most often employed fallacies, ad hominen means "to the man" and indicates an attack that is made upon a person rather than upon the statements that person has made.

An example is "Don't listen to my opponent; he's handicapped."

(7) The Fallacy of Faulty Analogy

Reasoning by analogy functions by comparing two similar things. Because they are alike in various ways, the fallacy is that it is likely they will share another trait as well. Faulty Analogy arguments draw similarities between the things compared that are not relevant to the characteristic being inferred in the conclusion.

Here's an example of a Faulty Analogy fallacy:

Ram and Shyam excel at both football and basketball. Since Ram is also a singer, it is likely that Shyam also excels at singing.

In this example, numerous similarities between Ram and Shyam are taken as the basis for the inference that they share additional traits.

(8) Straw Man

Here the speaker attributes an argument to an opponent that does not represent the opponent's true position.

For instance, a political candidate might charge that his opponent "wants to let all prisoners go free," when in fact his opponent simply favors a highly limited furlough system. The person is portrayed as someone that he is not.

(9) The "After This, Therefore, Because of This" Fallacy (Post hoc ergo propter hoc)

This is a "false cause" fallacy in which something is associated with something else because of mere proximity of time. One often encounters people assuming that because one thing happened after another, the first caused it, as with "I stood up; Sachin got out. My standing up resulted in a loss of wicket." The error in arguments that commit this fallacy is that their conclusions are causal claims that are not sufficiently substantiated by the evidence.

Here are two examples of the After This, Therefore Because of This Fallacy:

Ten minutes after walking into the auditorium, I began to feel sick to my stomach. There must have been something in the air in that building that caused my nausea.

In the first example, a causal connection is posited between two events simply on the basis of one occurring before the other. Without further evidence to support it, the causal claim based on the correlation is premature.

(10) The Either or Thinking

This is the so-called black or white fallacy. Essentially, it says "Either you believe what I'm saying, or you must believe exactly the opposite."

Here is an example of the black or white fallacy:

Since you don't believe that the earth is teetering on the edge of destruction, you must believe that pollution and other adverse effects that man has on the environment are of no concern whatsoever.

The argument above assumes that there are only two possible alternatives open to us. There is no room for a middle ground.

(11) The "All Things are Equal" Fallacy

This fallacy is committed when it is assumed, without justification, that background conditions have remained the same at different times/locations. In most instances, this is an unwarranted assumption for the simple reason that things rarely remain the same over extended periods of time, and things rarely remain the same from place to place.

The last time winner of south delhi constituency won the general election. This year, the winner of the south delhi constituency will win the general election.

The assumption operative in this argument is that nothing has changed since the last primary. No evidence or justification is offered for this assumption.

(12) The Fallacy of Equivocation

The Fallacy of Equivocation occurs when a word or phrase that has more than one meaning is employed in different meanings throughout the argument.

"Every society is, of course, repressive to some extent - as Sigmund Freud pointed out, repression is the price we pay for civilization."

In this example, the word repression is used in two completely different contexts. "Repression" in Freud's mind meant restricting sexual and psychological desires. "Repression" in the second context does not mean repression of individual desires, but government restriction of individual liberties, such as that in a totalitarian state.

(13) Non Sequitor

This means "does not follow," which is short for the conclusion does not follow from the premise. To say, "The house is white; therefore, it must be big" is an example of the Non Sequitor fallacy. It may be a big house, but there is no intrinsic connection with its being white.

(14) Argument ad populum

A group of children are playing, trying to determine no of balls in an opaque box. "I wonder if there are less than 4 or more than 4 balls in the box," says one student. "I know how we can tell!" pipes up another. "All right, how?" asks the teacher, resigned to the worst. Beams the child: "We can vote."

This is argumentum ad populum, the belief that truth can be determined by more or less putting it to a vote. Democracy is a very nice thing, but it doesn't determine truth. Polls are good for telling you what people think, not whether those thoughts are correct.

(15) Contradiction

Contradiction occurs when a writer asserts two opposing statements simultaneously. For example, saying "it is wet and it is dry" is a contradiction. Typical arguments on the test obscure the contradiction to the point that the argument can be quite compelling. Here's a great example:

We cannot know anyone, because we intuitively realize that people are unreliable.

At first glance this argument sounds reasonable, but "intuitively realize" means "to know." Thus the author is actually saying that we know that we don't know anyone. This is classic contradiction.

Typical Questions

Despite the wide variety of arguments used on the test, there are essentially only eight types of questions that are asked.

1) Assumption Questions

When a question asks you to find an author's assumption, it's asking you to find the statement without which the argument falls apart.Make use of denial technique. Simply negate the statement and see if the argument falls apart. If it does, that choice is the correct assumption. If, on the other hand, the argument is unaffected, the choice is wrong.

Below are stated some of the ways in which assumption questions are worded:

Which one of the following is assumed by the author?
Upon which one of the following assumptions does the author rely?
The argument depends on the assumption that. ..
Which one of the following, if added to the passage, will make the conclusion logical?
The validity of the argument depends on which one of the following?
The argument presupposes which one of the following?

2) Strengthen and Weaken Questions

An argument can be weakened by destroying a central piece of evidence or by attacking the validity of the author's assumptions. In contrast, an argument can be strengthened by providing additional support, by affirming the truth of an assumption or by presenting additional persuasive evidence.

Here are some of the ways in which strengthen/weaken the argument questions are worded:

Which one of the following, if true, would most weaken the argument?
Which one of the following, if true, would most strengthen the argument?
Which one of the following, if true, would most seriously damage the argument above?
Which one of the following, if true, casts the most doubt on the argument above?
Which one of the following, if true, is the most serious criticism of the argument above?
Which one of the following, if true, would provide the most support for the conclusion in the argument above?
The argument above would be more persuasive if which one of the following were found to be true?

3) Inference Questions

Inference questions require you to consider the statements as evidence and then draw a conclusion from them. A valid inference is something that must be true if the statements in the passage are true. It is an extension of the argument rather than a necessary part of it.

Inference questions probably have the most varied wording of all the Logical Reasoning question stems. Some are obvious, others are subtle, and still others may resemble other question types.

Below is the quick rundown of the various forms that inference questions are likely to take on your test:

Which one of the following can be inferred from the argument above?
The author suggests that. ..
If all the statements above are true, which one of the following must also be true?
The author of the passage would most likely agree with which one of the following?
The passage provides the most support for which one of the following?Which one of the following is probably the conclusion toward which the author is moving?

4) Flaw Questions

This question asks you to recognize what's wrong with an argument. Most critique the reasoning by pointing out a fallacy. Other flaw questions are more specific and attack the argument's reasoning.

Here are typical flaw questions:

Which one of the following contains a flaw that most closely parallels the flaw contained in the passage?
The speakers will not be able to settle their argument unless they
The conclusion above is unsound because
Which one of the following best identifies the flaw in the above argument?
In presenting her position the author does which one of the following?

5) Method of Argument Questions

Method-of-argument questions ask you to pick the choice that describes how the authorpresents her case. To tackle these, you must be able to analyze the structure of an argument. If you can't identify the evidence and conclusion, you'll have difficulty describing how an argument works.

Most questions involve classic argumentative structures, such as "arguing from a small sample to a larger group," or "inferring a causal relationship from a correlation." The other type of method-of-argument question gives a description of the argument in much more specific terms. Anexample of this might read, "The author presents his case in order to show that......"

6) Similar-Reasoning Questions

Similar-reasoning questions require you to identify the answer that contains the reasoning most similar to that in the stimulus. The key is to summarize the argument's overall form and match it to that of the correct choice. A good approach to these questions is to see if the argument can be symbolized algebraically, using Xs and Ys.

Example: All fish swim. This creature swims. Therefore, it must be a fish.

This (flawed) argument can be symbolized in the following way:

All X do Y. This does Y. Therefore, this must be an X.

If the stimulus can be symbolized this way, your job will be to search for the choice that can be symbolized in the same way. Your answer might look something like this:

Every mother (all X) loves singing (does Y). Jenny is singing (this does Y). So she must be a mother. (therefore, this must be an X).

7) Paradox Questions

When an argument contains two or more seemingly inconsistent statements, it presents a paradox. Most paradoxical arguments end with a contradiction. Another type of paradox has the argument build to a certain point, then change to the exact opposite of what you expect.

In a typical paradox question, you'll be asked either to find the choice that "explains the paradoxical result", "explains the inconsistent findings", or "resolves the apparent discrepancy." This will be the choice that reconciles the seemingly inconsistent statements in the argument while allowing them all to still be true.

8) Principle Questions

Principle questions ask you to apply a specific situation into a global generality (or vice versa). You may be given an argument and asked to find the principle that justifies the author's reasoning.

Possible question stems:

The author's position most closely conforms to which one of the following principles?
What principle best accounts for or justifies the author's position?
Which one of the following principles would justify Al's refusal to follow the author's recommendation

The correct answer to principle questions expresses the key concepts and contains the key terms that the other choices omit. Avoid choices that are beyond the scope of the argument. Most of the wrong choices contain principles that sound formal and look reasonable, but they don't address the author's main concern.