Critical Reasoning

Environmentalist: The commissioner of the Fish and Game Authority would have the public believe that increases in the number of marine fish caught demonstrate that this resource is no longer endangered. This is a specious argument, as unsound as it would be to assert that the ever-increasing rate at which rain forests are being cut down demonstrates a lack of danger to that resource. The real cause of the increased fish-catch is a greater efficiency in using technologies that deplete resources. Which of the following strategies is used in the presentation of the environmentalist's position?

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?

Rural households have more purchasing power than do urban or suburban households at the same income level, since some of the income urban and suburban households use for food and shelter can be used by rural households for other needs. Which of the following inferences is best supported by the statement made above?

Opponents of laws that require automobile drivers and passengers to wear seat belts argue that in a free society people have the right to take risks as long as people do not harm others as a result of taking the risks. As a result, they conclude that it should be each person�s decision whether or not to wear a seat belt. Which of the following, if true, most seriously weakens the conclusion drawn above?

Adult female rats who have never before encountered rat pups will start to show maternal behaviors after being confined with a pup for about seven days. This period can be considerably shortened by disabling the female's sense of smell or by removing the scent-producing glands of the pup. Which of the following hypotheses best explains the contrast described above?

The proposal to hire ten new police officers in Middletown is quite foolish. There is sufficient funding to pay the salaries of the new officers, but not the salaries of additional court and prison employees to process the increased caseload of arrests and convictions that new officers usually generate. Which of the following, if true, will most seriously weaken the conclusion drawn above?

With the emergence of biotechnology companies, it was feared that they would impose silence about proprietary results on their in-house researchers and their academic consultants. This constraint, in turn, would slow the development of biological science and engineering. Which of the following, if true, would tend to weaken most seriously the prediction of scientific secrecy described above?

Mourdet Winery: Danville Winery's new wine was introduced to compete with our most popular wine, which is sold in a distinctive tall, black bottle. Danville uses a similar bottle. Thus, it is likely that many customers intending to buy our wine will mistakenly buy theirs instead. Danville Winery: Not so. The two bottles can be readily distinguished: the label on ours, but not on theirs, is gold colored. Which of the following, if true, most undermines Danville Winery's response?

The Official Guide for GMAT Review, 11th Edition, 2005 Practice Question Question No.: CR 88 Page: 493Networks of blood vessels in bats� wings serve only to disperse heat generated in flight. This heat is generated only because bats flap their wings. Thus paleontologists� recent discovery that the winged dinosaur Sandactylus had similar networks of blood vessels in the skin of its wings provides evidence for the hypothesis that Sandactylus flew by flapping its wings, not just by gliding. Which of the following, if true, most seriously weakens the argument in the passage?

Biometric access-control systems�those using fingerprints, voice prints, etc., to regulate admittance to restricted areas�work by degrees of similarity, not by identity. After all, even the same finger will rarely leave exactly identical prints. Such systems can be adjusted to minimize refusals of access to legitimate access-seekers. Such adjustments, however, increase the likelihood of admitting impostors. Which of the following conclusions is most strongly supported by the information above?

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. The author is arguing that ________________.

Roland: The alarming fact is that 90 percent of the people in this country now report that they know someone who is unemployed. Sharon: But a normal, moderate level of unemployment is 5 percent, with 1 out of 20 workers unemployed. So at any given time if a person knows approximately 50 workers, 1 or more will very likely be unemployed. Sharon's argument is structured to lead to which of the following as a conclusion?

During the Second World War, about 375,000 civilians died in the United States and about 408,000 members of the United States armed forces died overseas. On the basis of those figures, it can be concluded that it was not much more dangerous to be overseas in the armed forces during the Second World War than it was to stay at home as a civilian. Which of the following would reveal most clearly the absurdity of the conclusion drawn above?

Editorial: Regulations recently imposed by the government of Risemia call for unprecedented reductions in the amounts of pollutants manufacturers are allowed to discharge into the environment. It will take costly new pollution control equipment requiring expensive maintenance to comply with these regulations. Resultant price increases for Risemian manufactured goods will lead to the loss of some export markets. Clearly, therefore, annual exports of Risemian manufactured goods will in the future occur at diminished levels. Which of the following, if true, most seriously weakens the argument in the editorial?

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?

Bank depositors in the United States are all financially protected against bank failure because the government insures all individuals' bank deposits. An economist argues that this insurance is partly responsible for the high rate of bank failures, since it removes from depositors any financial incentive to find out whether the bank that holds their money is secure against failure. If depositors were more selective, then banks would need to be secure in order to compete for depositors' money. The economist's argument makes which of the following assumptions?

Editorial: The mayor plans to deactivate the city�s fire alarm boxes, because most calls received from them are false alarms. The mayor claims that the alarm boxes are no longer necessary, since most people now have access to either public or private telephone. But the city�s commercial district, where there is the greatest risk of fire, has few residents and few public telephones, so some alarm boxes are still necessary. Which of the following, if true, most seriously weakens the editorial�s argument?

The ice on the front windshield of the car had formed when moisture condensed during the night. The ice melted quickly after the car was warmed up the next morning because the defrosting vent, which blows on the front windshield, was turned on full force. Which of the following, if true, most seriously jeopardizes the validity of the explanation for the speed with which the ice melted?

Country Y uses its scarce foreign-exchange reserves to buy scrap iron for recycling into steel. Although the steel thus produced earns more foreign exchange than it costs, that policy is foolish. Country Y�s own territory has vast deposits of iron ore, which can be mined with minimal expenditure of foreign exchange. Which of the following, if true, provides the strongest support for Country Y�s policy of buying scrap iron abroad?

According to a review of 61 studies of patients suffering from severely debilitating depression, a large majority of the patients reported that missing a night's sleep immediately lifted their depression. Yet sleep deprivation is not used to treat depression even though the conventional treatments, which use drugs and electric shocks, often have serious side effects. Which of the following, if true, best explains the fact that sleep deprivation is not used as a treatment for depression?