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GMAT - Critical Reasoning - Test 12

in Critical Reasoning

Read the passage and choose the option that best answer the question.

1. In research designed to investigate the possibility of animals developing friendship with other, unrelated, members of their species, a group of 29 chimpanzees were reared together for 15 years. At the end of that time the chimps were presented with two options for obtaining food: press a lever and feed themselves, or press another identical lever and feed themselves, and at the same time deliver food to the chimp next door. (The chimps were able to see each other). The researchers found that the chimps were no more likely to choose the lever that fed a neighbor. The researchers concluded that the chimps had no concept of friendship. However, one critic has suggested that the animals were in an artificial environment from which little can be concluded, and that, at the least, the test ought to have involved the animals being able to touch.

What role do the parts in boldface play in the argument above?

A. The first is a position that the critic opposes. The second is a position that the critic supports.
B. The first is an observation that supports the researchers? position. The second is an observation that opposes the researchers? position.
C. The first is a finding on which the researchers base their conclusion. The second is a suggestion that might cast doubt on that finding.
D. The first is an observation that supports the critic?s conclusion. The second is the critic?s conclusion.
E. The first is part of the evidence that the critic disputes. The second is a suggestion that the researchers do not accept.

2. Determining the authenticity of purported pre-Columbian artifacts is never easy. Carbon-14 dating of these artifacts is often impossible due to contamination by radioactive palladium (which occurs naturally in the soils of Central and South America). However, historians and anthropologists have evolved two reliable criteria, which, utilized in combination, have proven effective for dating these artifacts. First, because authentic pre-Columbian artifacts characteristically occur in a coarse, granular matrix that is shifted by major earthquakes, they often exhibit the unique scratch patterns known as gridding. In addition, true pre-Columbian artifacts show a darkening in surface color that is caused by centuries of exposure to the minute amounts of magnesium in the soil of the Americas. The criteria above would be LEAST useful in judging the authenticity of which of the following?

A. An ax head of black obsidian, unearthed from a kitchen midden
B. A pottery bowl with a red ocher design, found in the ruins of a temple
C. A set of gold ear weights, ornamented with jasper pendants
D. A black feather cape from a king's burial vault
E. A multicolored woven sash found near the gravesite of a slave

3. A nutritionist studying the effects of massive doses of vitamin C found that of a group of 600 people who regularly took 1,500 mg of vitamin C daily for a year, fewer than 9 percent suffered serious cases of flu; of a group of 600 people who took 250 mg of vitamin C (the standard recommended daily allowance) daily for a year, 34 percent suffered at least one serious case of flu; and of a group of 600 people who took no vitamin C for a year (other than that found in the foods in a balanced diet), 32 percent suffered at least one serious case of flu. Which of the following hypotheses is best supported by the evidence above?

A. The effectiveness of vitamin C in preventing serious cases of flu increases in direct proportion to the amount of vitamin C taken.
B. Vitamin C is helpful in preventing disease.
C. Doses of vitamin C that exceed the standard recommended daily allowance by 500 percent will reduce the incidence of serious cases of flu by 25 percent.
D. Massive doses of vitamin C can help to prevent serious case of flu.
E. A balanced diet contains less than 250 mg of vitamin C.

4. Traffic safety experts predict that the installation of newly designed air bags in all cars in the United States would reduce the average number of fatalities per traffic accident by 30 percent. In order to save lives, the Department of Transportation (DOT) is considering requiring automobile manufacturers to install air bags of this design in all cars produced after 1998. Which of the following, if true, represents the strongest challenge to the DOT's proposal?

A. Air bags of the new design are more given to being inadvertently triggered, an occurrence that can sometimes result in fatal traffic accidents.
B. The DOT is planning to require automobile manufacturers to produce these air bags according to very strict specifications.
C. After installing air bags in new cars, automobile manufacturers will experience an increase in sales.
D. The proposed air bag installation program will adversely affect the resale of cars manufactured prior to 1998.
E. As production costs increase, the profits of many domestic automobile dealers show a marked decrease.

5. Identical twins tend to have similar personalities; if environment outweighs heredity in personality development, twins raised together should presumably have more similar personalities than those raised apart. A recent study of identical twins in both situations measured 11 key traits through a questionnaire, and concluded that 7 of the 11 are primarily products of heredity. Which of the following, if established, would cast the most doubt on the study's results?

A. Fewer than half of the pairs of twins studied were raised separately.
B. The ages of all of the twins studied fell within a 10-year range.
C. Some of the traits that the study attributed to heredity developed in the separately raised twins because those pairs all grew up in similar families.
D. Although over half the traits measured were determined to be linked to heredity, the nature of those traits varied widely.
E. The 11 traits that were measured constitute a representative sample of larger, generally accepted pool of key personality traits.

6. Kale has more nutritional value than spinach. But since collard greens have more nutritional value than lettuce, it follows that kale has more nutritional value than lettuce. Any of the following, if introduced into the argument as an additional premise, makes the argument above logically correct EXCEPT:

A. Collard greens have more nutritional value than kale.
B. Spinach has more nutritional value than lettuce.
C. Spinach has more nutritional value than collard greens.
D. Spinach and collard greens have the same nutritional value.
E. Kale and collard greens have the same nutritional value.

7. The number of musicians employed to play accompaniment for radio and television commercials has sharply decreased over the past ten years. This has occurred even though the number of commercials produced each year has not significantly changed for the last ten years. Which of the following, if it occurred during the past ten years, would contribute LEAST to an explanation of the facts above?

A. The type of music most popular for use in commercials has changed from a type that requires a large number of instruments to a type that requires very few instruments.
B. There has been an increase in the number of commercials that use only the spoken word and sound effects, rather than musical accompaniment.
C. There has been an increase in the number of commercials that use a synthesizer, an instrument on which one musician can reproduce the sound of many musicians playing together.
D. There has been an increase in the number of commercials that use prerecorded music as their only source of music.
E. There has been an increase in the number of commercials that use musicians just starting in the music industry rather than musicians experienced in accompanying commercials.

8. For a trade embargo against a particular country to succeed, a high degree of both international accord and ability to prevent goods from entering or leaving that country must be sustained. A total blockade of Patria's ports is necessary to an embargo, but such an action would be likely to cause international discord over the embargo. The claims above, if true, most strongly support which of the following conclusions?

A. The balance of opinion is likely to favor Patria in the event of a blockade.
B. As long as international opinion is unanimously against Patria, a trade embargo is likely to succeed.
C. A naval blockade of Patria's ports would ensure that no goods enter or leave Patria.
D. Any trade embargo against Patria would be likely to fail at some time.
E. For a blockade of Patria's ports to be successful, international opinion must be unanimous.

9. Purebred cows native to Mongolia produce, on average, 400 liters of milk per year; if Mongolian cattle are crossbred with European breeds, the crossbred cows can produce, on average, 2,700 liters per year. An international agency plans to increase the profitability of Mongolia's dairy sector by encouraging widespread crossbreeding of native Mongolian cattle with European breeds. Which of the following, if true, casts the most serious doubt on the viability of the agency's plan?

A. Not all European breeds of cattle can be successfully bred with native Mongolian cattle.
B. Many young Mongolians now regard cattle raising as a low-status occupation because it is less lucrative than other endeavors open to them.
C. Mongolia's terrain is suitable for grazing native herds but not for growing the fodder needed to keep crossbred animals healthy.
D. Cowhide and leather products, not milk, make up the bulk of Mongolia's animal product exports to Europe.
E. Many European breeds of cattle attain average milk production levels exceeding 2,700 liters.

10. Left-handed persons suffer more frequently than do right-handed persons from certain immune disorders, such as allergies. Left-handers tend to have an advantage over the right-handed majority, however, on tasks controlled by the right hemisphere of the brain, and mathematical reasoning is strongly under the influence of the right hemisphere in most people. If the information above is true, it best supports which of the following hypotheses?

A. Most people who suffer from allergies or other such immune disorders are left-handed rather than right-handed.
B. Most left-handed mathematicians suffer from some kind of allergy.
C. There are proportionally more left-handers among people whose ability to reason mathematically is above average than there are among people with poor mathematical reasoning ability.
D. If a left-handed person suffers from an allergy, that person will probably be good at mathematics.
E. There are proportionally more people who suffer from immune disorders such as allergies than there are people who are left-handed or people whose mathematical reasoning ability is unusually good.