2013年GMAT考试最新逻辑推理试题训练九

查看汇总：2013年GMAT考试最新逻辑推理试题训练汇总

　　1. After the national speed limit of 55 miles per hour was imposed in 1974, the number of deaths per mile driven on a highway fell abruptly as a result. Since then, however, the average speed of vehicles on highways has risen, but the number of deaths per mile driven on a highway has continued to fall. Which of the following conclusions can be properly drawn from the statements above?

　　(A) The speed limit alone is probably not responsible for the continued reduction in highway deaths in the years after 1974.

　　(B) People have been driving less since 1974.

　　(C) Driver-education courses have been more effective since 1974 in teaching drivers to drive safely.

　　(D) In recent years highway patrols have been less effective in catching drivers who speed.

　　(E) The change in the speed limit cannot be responsible for the abrupt decline in highway deaths in 1974.

　　2. Neighboring landholders: Air pollution from the giant aluminum refinery that has been built next to our land is killing our plants.Company spokesperson: The refinery is not to blame, since our study shows that the damage is due to insects and fungi.Which of the following, if true, most seriously weakens the conclusion drawn by the company spokesperson?

　　(A) The study did not measure the quantity of pollutants emitted into the surrounding air by the aluminum refinery.

　　(B) The neighboring landholders have made no change in the way they take care of their plants.

　　(C) Air pollution from the refinery has changed the chemical balance in the plants’ environment, allowing the harmful insects and fungi to thrive.

　　(D) Pollutants that are invisible and odorless are emitted into the surrounding air by the refinery.

　　(E) The various species of insects and fungi mentioned in the study have been occasionally found in the locality during the past hundred years.

　　3. Sales taxes tend to be regressive, affecting poor people more severely than wealthy people. When all purchases of consumer goods are taxed at a fixed percentage of the purchase price, poor people pay a larger proportion of their income in sales taxes than wealthy people do.It can be correctly inferred on the basis of the statements above that which of the following is true?

　　(A) Poor people constitute a larger proportion of the taxpaying population than wealthy people do.

　　(B) Poor people spend a larger proportion of their income on purchases of consumer goods than wealthy people do.

　　(C) Wealthy people pay, on average, a larger amount of sales taxes than poor people do.

　　(D) The total amount spent by all poor people on purchases of consumer goods exceeds the total amount spent by all wealthy people on consumer goods.

　　(E) The average purchase price of consumer goods bought by wealthy people is higher than that of consumer goods bought by poor people.

　　4. Reviewing historical data, medical researchers in California found that counties with the largest number of television sets per capita have had the lowest incidence of a serious brain disease, mosquito-borne encephalitis. The researchers have concluded that people in these counties stay indoors more and thus avoid exposure to the disease.The researchers’ conclusion would be most strengthened if which of the following were true?

　　(A) Programs designed to control the size of disease-bearing mosquito populations have not affected the incidence of mosquito borne encephalitis.

　　(B) The occupations of county residents affect their risk of exposure to mosquito-borne encephalitis more than does television-watching.

　　(C) The incidence of mosquito-borne encephalitis in counties with the largest number of television sets per capita is likely to decrease even further.

　　(D) The more time people in a county spend outdoors, the greater their awareness of the dangers of mosquito-borne encephalitis.

　　(E) The more television sets there are per capita in a county, the more time the average county resident spends watching television.

　　5. The city’s public transportation system should be removed from the jurisdiction of the municipal government, which finds it politically impossible either to raise fares or to institute cost-saving reductions in service. If public transportation were handled by a private firm, profits would be vigorously pursued, thereby eliminating the necessity for covering operating costs with government funds.The statements above best support the conclusion that

　　(A) the private firms that would handle public transportation would have experience in the transportation industry

　　(B) political considerations would not prevent private firms from ensuring that revenues cover operating costs

　　(C) private firms would receive government funding if it were needed to cover operating costs

　　(D) the public would approve the cost-cutting actions taken by the private firm

　　(E) the municipal government would not be resigned to accumulating merely enough income to cover costs

　　6. To entice customers away from competitors, Red Label supermarkets have begun offering discounts on home appliances to customers who spend $50 or more on any shopping trip to Red Label. Red Label executives claim that the discount program has been a huge success, since cash register receipts of $50 or more are up thirty percent since the beginning of the program.Which of the following, if true, most seriously weakens the claim of the Red Label executives?

　　(A) Most people who switched to Red Label after the program began spend more than $50 each time they shop at Red Label.

　　(B) Most people whose average grocery bill is less than $50 would not be persuaded to spend more by any discount program.

　　(C) Most people who received discounts on home appliances through Red Label’s program will shop at Red Label after the program ends.

　　(D) Since the beginning of the discount program, most of the people who spend $50 or more at Red Label are people who have never before shopped there and whose average grocery bill has always been higher than $50.

　　(E) Almost all of the people who have begun spending $50 or more at Red Label since the discount program began are longtime customers who have increased the average amount of their shopping bills by making fewer trips.

　　7. Throughout the 1950’s, there were increases in the numbers of dead birds found in agricultural areas after pesticide sprayings. Pesticide manufacturers claimed that the publicity given to bird deaths stimulated volunteers to look for dead birds, and that the increase in numbers reported was attributable to the increase in the number of people looking.Which of the following statements, if true, would help to refute the claim of the pesticide manufacturers?

　　(A) The publicity given to bird deaths was largely regional and never reached national proportions.

　　(B) Pesticide sprayings were timed to coincide with various phases of the life cycles of the insects they destroyed.

　　(C) No provision was made to ensure that a dead bird would not be reported by more than one observer.

　　(D) Initial increases in bird deaths had been noticed by agricultural workers long before any publicity had been given to the matter.

　　(E) Dead birds of the same species as those found in agricultural areas had been found along coastal areas where no farming took place.

　　8. Teenagers are often priced out of the labor market by the government-mandated minimum-wage level because employers cannot afford to pay that much for extra help. Therefore, if Congress institutes a subminimum wage, a new lower legal wage for teenagers, the teenage unemployment rate, which has been rising since 1960, will no longer increase.Which of the following, if true, would most weaken the argument above?

　　(A) Since 1960 the teenage unemployment rate has risen when the minimum wage has risen.

　　(B) Since 1960 the teenage unemployment rate has risen even when the minimum wage remained constant.

　　(C) Employers often hire extra help during holiday and warm weather seasons.

　　(D) The teenage unemployment rate rose more quickly in the 1970’s than it did in the 1960’s.

　　(E) The teenage unemployment rate has occasionally declined in the years since 1960.

　　9. Which of the following best completes the passage below?The computer industry’s estimate that it loses millions of dollars when users illegally copy programs without paying for them is greatly exaggerated. Most of the illegal copying is done by people with no serious interest in the programs. Thus, the loss to the industry is much smaller than estimated because______

　　(A) many users who illegally copy programs never find any use for them

　　(B) most of the illegally copied programs would not be purchased even if purchasing them were the only way to obtain them

　　(C) even if the computer industry received all the revenue it claims to be losing, it would still be experiencing financial difficulties

　　(D) the total market value of all illegal copies is low in comparison to the total revenue of the computer industry

　　(E) the number of programs that are frequently copied illegally is low in comparison to the number of programs available for sale

　　10. This year the New Hampshire Division of Company X set a new record for annual sales by that division. This record is especially surprising since the New Hampshire Division has the smallest potential market and the lowest sales of any of Company X’s divisions.Which of the following identifies a flaw in the logical coherence of the statement above?

　　(A) If overall sales for Company X were sharply reduced, the New Hampshire Division’s new sales record is irrelevant to the company’s prosperity.

　　(B) Since the division is competing against its own record, the comparison of its sales record with that of other divisions is irrelevant.

　　(C) If this is the first year that the New Hampshire Division has been last in sales among Company X’s divisions, the new record is not surprising at all.

　　(D) If overall sales for Company X were greater than usual, it is not surprising that the New Hampshire Division was last in sales.

　　(E) Since the New Hampshire Division has the smallest potential market, it is not surprising that it had the lowest sales.

　　11. Statement of a United States copper mining company: Import quotas should be imposed on the less expensive copper mined outside the country to maintain the price of copper in this country; otherwise, our companies will not be able to stay in business.Response of a United States copper wire manufacturer: United States wire and cable manufacturers purchase about 70 percent of the copper mined in the United States. If the copper prices we pay are not at the international level, our sales will drop, and then the demand for United States copper will go down.If the factual information presented by both companies is accurate, the best assessment of the logical relationship between the two arguments is that the wire manufacturer’s argument

　　(A) is self-serving and irrelevant to the proposal of the mining company

　　(B) is circular, presupposing what it seeks to prove about the proposal of the mining company

　　(C) shows that the proposal of the mining company would have a negative effect on the mining company’s own business

　　(D) fails to give a reason why the proposal of the mining company should not be put into effect to alleviate the concern of the mining company for staying in business

　　(E) establishes that even the mining company’s business will prosper if the mining company’s proposal is rejected

　　12. Y has been believed to cause Z. A new report, noting that Y and Z are often observed to be preceded by X, suggests that X, not Y, may be the cause of Z.Which of the following further observations would best support the new report’s suggestion?

　　(A) In cases where X occurs but Y does not, X is usually followed by Z.

　　(B) In cases where X occurs, followed by Y, Y is usually followed by Z.

　　(C) In cases where Y occurs but X does not, Y is usually followed by Z.

　　(D) In cases where Y occurs but Z does not, Y is usually preceded by X.

　　(E) In cases where Z occurs, it is usually preceded by X and Y.

　　13. Mr. Primm: If hospitals were private enterprises, dependent on profits for their survival, there would be no teaching hospitals, because of the intrinsically high cost of running such hospitals.Ms. Nakai: I disagree. The medical challenges provided by teaching hospitals attract the very best physicians. This, in turn, enables those hospitals to concentrate on nonroutine cases.Which of the following, if true, would most strengthen Ms. Nakai’s attempt to refute Mr. Primm’s claim?

　　(A) Doctors at teaching hospitals command high salaries.

　　(B) Sophisticated, nonroutine medical care commands a high price.

　　(C) Existing teaching hospitals derive some revenue from public subsidies.

　　(D) The patient mortality rate at teaching hospitals is high.

　　(E) The modern trend among physicians is to become highly specialized.

　　14. A recent survey of all auto accident victims in Dole County found that, of the severely injured drivers and front-seat passengers, 80 percent were not wearing seat belts at the time of their accidents. This indicates that, by wearing seat belts, drivers and front-seat passengers can greatly reduce their risk of being severely injured if they are in an auto accident.The conclusion above is not properly drawn unless which of the following is true?

　　(A) Of all the drivers and front-seat passengers in the survey, more than 20 percent were wearing seat belts at the time of their accidents.

　　(B) Considerably more than 20 percent of drivers and front-seat passengers in Dole County always wear seat belts when traveling by car.

　　(C) More drivers and front-seat passengers in the survey than rear-seat passengers were very severely injured.

　　(D) More than half of the drivers and front-seat passengers in the survey were not wearing seat belts at the time of their accidents.

　　(E) Most of the auto accidents reported to police in Dole County do not involve any serious injury.

　　15. Six months or so after getting a video recorder, many early buyers apparently lost interest in obtaining videos to watch on it. The trade of businesses selling and renting videos is still buoyant, because the number of homes with video recorders is still growing. But clearly, once the market for video recorders is saturated, businesses distributing videos face hard times.Which of the following, if true, would most seriously weaken the conclusion above?

　　(A) The market for video recorders would not be considered saturated until there was one in 80 percent of homes.

　　(B) Among the items handled by video distributors are many films specifically produced as video features.

　　(C) Few of the early buyers of video recorders raised any complaints about performance aspects of the new product.

　　(D) The early buyers of a novel product are always people who are quick to acquire novelties, but also often as quick to tire of them.

　　(E) In a shrinking market, competition always intensifies and marginal businesses fail.

　　16. Advertiser: The revenue that newspapers and magazines earn by publishing advertisements allows publishers to keep the prices per copy of their publications much lower than would otherwise be possible. Therefore, consumers benefit economically from advertising.Consumer: But who pays for the advertising that pays for low-priced newspapers and magazines? We consumers do, because advertisers pass along advertising costs to us through the higher prices they charge for their products.Which of the following best describes how the consumer counters the advertiser’s argument?

　　(A) By alleging something that, if true, would weaken the plausibility of the advertiser’s conclusion

　　(B) By questioning the truth of the purportedly factual statement on which the advertiser’s conclusion is based

　　(C) By offering an interpretation of the advertiser’s opening statement that, if accurate, shows that there is an implicit contradiction in it

　　(D) By pointing out that the advertiser’s point of view is biased

　　(E) By arguing that the advertiser too narrowly restricts the discussion to the effects of advertising that are economic

　　17. Mr. Lawson: We should adopt a national family policy that includes legislation requiring employers to provide paid parental leave and establishing government-sponsored day care. Such laws would decrease the stress levels of employees who have responsibility for small children. Thus, such laws would lead to happier, better-adjusted families.Which of the following, if true, would most strengthen the conclusion above?

　　(A) An employee’s high stress level can be a cause of unhappiness and poor adjustment for his or her family.

　　(B) People who have responsibility for small children and who work outside the home have higher stress levels than those who do not.

　　(C) The goal of a national family policy is to lower the stress levels of parents.

　　(D) Any national family policy that is adopted would include legislation requiring employers to provide paid parental leave and establishing government-sponsored day care.

　　(E) Most children who have been cared for in daycare centers are happy and well adjusted.

　　18. Lark Manufacturing Company initiated a voluntary Quality Circles program for machine operators. Independent surveys of employee attitudes indicated that the machine operators participating in the program were less satisfied with their work situations after two years of the program’s existence than they were at the program’s start. Obviously, any workers who participate in a Quality Circles program will, as a result, become less satisfied with their jobs.Each of the following, if true, would weaken the conclusion drawn above EXCEPT:

　　(A) The second survey occurred during a period of recession when rumors of cutbacks and layoffs at Lark Manufacturing were plentiful.

　　(B) The surveys also showed that those Lark machine operators who neither participated in Quality Circles nor knew anyone who did so reported the same degree of lessened satisfaction with their work situations as did the Lark machine operators who participated in Quality Circles.

　　(C) While participating in Quality Circles at Lark Manufacturing, machine operators exhibited two of the primary indicators of improved job satisfaction: increased productivity and decreased absenteeism.

　　(D) Several workers at Lark Manufacturing who had participated in Quality Circles while employed at other companies reported that, while participating in Quality Circles in their previous companies, their work satisfaction had increased.

　　(E) The machine operators who participated in Quality Circles reported that, when the program started, they felt that participation might improve their work situations.

　　Questions 19-20 are based on the following.

　　Blood banks will shortly start to screen all donors for NANB hepatitis. Although the new screening tests are estimated to disqualify up to 5 percent of all prospective blood donors, they will still miss two-thirds of donors carrying NANB hepatitis. Therefore, about 10 percent of actual donors will still supply NANB-contaminated blood.

　　19. The argument above depends on which of the following assumptions?

　　(A) Donors carrying NANB hepatitis do not, in a large percentage of cases, carry other infections for which reliable screening tests are routinely performed.

　　(B) Donors carrying NANB hepatitis do not, in a large percentage of cases, develop the disease themselves at any point.

　　(C) The estimate of the number of donors who would be disqualified by tests for NANB hepatitis is an underestimate.

　　(D) The incidence of NANB hepatitis is lower among the potential blood donors than it is in the population at large.

　　(E) The donors who will still supply NANB-contaminated blood will donate blood at the average frequency for all donors.

　　20. Which of the following inferences about the consequences of instituting the new tests is best supported by the passage above?

　　(A) The incidence of new cases of NANB hepatitis is likely to go up by 10 percent.

　　(B) Donations made by patients specifically for their own use are likely to become less frequent.

　　(C) The demand for blood from blood banks is likely to fluctuate more strongly.

　　(D) The blood supplies available from blood banks are likely to go down.

　　(E) The number of prospective first-time donors is likely to go up by 5 percent.

　　参考答案:

　　1. A2. C3. B4. E5. B

　　6. E7. D8. B9. B10. B

　　11. C12. A13. B14. A15. D

　　16. A17. A18. E19. A20. D