GMAT复习资料——逻辑重点题难题集（一）

kuaijizu

Economist: On average, the emergency treatment for an elderly person for injuries resulting from a fall costs $11,000. A new therapeutic program can significantly reduce an elderly person's chances of falling. Though obviously desirable for many reasons, this treatment program will cost $12,500 and thus cannot be justified.
Which of the following, if true, most seriously undermines the conclusion of the argument?
(A) Among elderly people who had followed the program for only a few months, the number of serious falls reported was higher than it was for people who had followed the program for its recommended minimum length of one year.
(B) Falls resulting in serious injuries are less common among elderly people living in nursing homes than they are among elderly people who live alone at home.
(C) A frequent result of injuries sustained in falls is long-term pain, medication for which is not counted among the average per-person costs of emergency treatment for elderly people's injuries from such falls.
(D) The new therapeutic program focuses on therapies other than medication, since overmedication can cause disorientation and hence increase the likelihood that an elderly person will have a serious fall.
(E) A significant portion of the cost of the new therapeutic program is represented by regular visits by health care professionals, the costs of which tend to increase more rapidly than do those of other elements of the program.
答案为C。根据题意，正确答案一定是从cost角度来说明该program其实是justified.

kuaijizu

Tiger sharks are common in the waters surrounding Tenare Island.  Usually tiger sharks feed on smaller sharks, but sometimes they have attacked tourists swimming and surfing at Tenare's beaches.  This has hurt Tenare's tourism industry, which is second only to its fishing industry in annual revenues.  In order to help the economy, therefore, the mayor of the island has proposed an ongoing program to kill any tiger sharks within a mile of the beaches.
Which of the following, if true, most strongly calls into question the likelihood that implementation of the mayor's proposal will have the desired consequence?
(A) Even if not all the tiger sharks that come close to the beaches are killed, the existence of the program would reassure tourists.
(B) Business owners who depend on tourism are willing to pay most of the cost of implementing the program.
(C) Tourists come to Tenare Island for its beaches, even though the island features a number of other tourist attractions.
(D) The small sharks on which tiger sharks prey feed on fish that are commercially important to the island's fisheries.
(E) Not all tourists who come to Tenare Island enjoy swimming or surfing.
答案为D。根据题意，正确答案一定是从economy的角度来考虑，注意D选项句子结构比较复杂，阅读时必须仔细。

kuaijizu

Finding of a survey of Systems magazine subscribers:  Thirty percent of all merchandise orders placed by subscribers in response to advertisements in the magazine last year were placed by subscribers under age thirty-five.
Finding of a survey of advertisers in Systems magazine:  Most of the merchandise orders placed in response to advertisements in Systems last year were placed by people under age thirty-five.
For both of the findings to be accurate, which of the following must be true?
(A) More subscribers to Systems who have never ordered merchandise in response to advertisements in the magazine are age thirty-five or over than are under age thirty-five.
(B) Among subscribers to Systems, the proportion who are under age thirty-five was considerably lower last year than it is now.
(C) Most merchandise orders placed in response to advertisements in Systems last year were placed by Systems subscribers over age thirty-five.
(D) Last year, the average dollar amount of merchandise orders placed was less for subscribers under age thirty-five than for those age thirty-five or over.
(E) Last year many people who placed orders for merchandise in response to advertisements in Systems were not subscribers to the magazine.
答案为E。本题为数字归纳题，做题时需要仔细阅读原文，想清subscriber和people的包含关系（后者包含前者）。

kuaijizu

From 1978 to 1988, beverage containers accounted for a steadily decreasing percentage of the total weight of household garbage in the United States.  The increasingly widespread practice of recycling aluminum and glass was responsible for most of this decline.  However, although aluminum recycling was more widely practiced in this period than glass recycling, it was found that the weight of glass bottles in household garbage declined by a greater percentage than the weight of aluminum cans.
Which of the following, if true of the United States in the period 1978 to 1988, most helps to account for the finding?
(A) Glass bottles are significantly heavier than aluminum cans of comparable size.
(B) Recycled aluminum cans were almost all beverage containers, but a significant fraction of the recycled glass bottles had contained products other than beverages.
(C) Manufacturers replaced many glass bottles, but few aluminum cans, with plastic containers.
(D) The total weight of glass bottles purchased by households increased at a slightly faster rate than the total weight of aluminum cans.
(E) In many areas, glass bottles had to be sorted by color of the glass before being recycled, whereas aluminum cans required no sorting.
答案为C。完成本题的关键就是要看清题目比较的是the weight of glass bottles in household garbage这个percentage。

kuaijizu

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.
答案为C。完成本题的关键在于理解题目讨论的测试结果是inconclusive结果，而不是truthful或untruthful结果。

kuaijizu

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?
(A) For a small percentage of depressed patients, missing a night's sleep induces a temporary sense of euphoria.
(B) Keeping depressed patients awake is more difficult than keeping awake people who are not depressed.
(C) Prolonged loss of sleep can lead to temporary impairment of judgment comparable to that induced by consuming several ounces of alcohol.
(D) The dramatic shifts in mood connected with sleep and wakefulness have not been traced to particular changes in brain chemistry.
(E) Depression returns in full force as soon as the patient sleeps for even a few minutes.
答案为E。注意本题讨论的只是sleep-deprivation方法是否可以缓解depression，而与其他judgment impairment什么的无关。

kuaijizu

Which of the following most logically completes the argument?
A new machine for harvesting corn will allow rows to be planted only fifteen inches apart, instead of the usual thirty inches.  Corn planted this closely will produce lower yields per plant.  Nevertheless, the new machine will allow corn growers to double their profits per acre because __________.
(A) with the closer spacing of the rows, the growing corn plants will quickly form a dense canopy of leaves, which will, by shading the ground, minimize the need for costly weed control and irrigation
(B) with the closer spacing of the rows, corn plants will be forced to grow taller because of increased competition for sunlight from neighboring corn plants
(C) with the larger number of plants growing per acre, more fertilizer will be required
(D) with the spacing between rows cut by half, the number of plants grown per acre will almost double
(E) with the closer spacing of the rows, the acreage on which corn is planted will be utilized much more intensively than it was before, requiring more frequent fallow years in which corn fields are left unplanted
答案为A。注意本题讨论的是profit。选项D错误的原因是结合本句和原文第二句可知在该条件下profit同样不会double。

kuaijizu

Radio stations with radio data system (RDS) technology broadcast special program information that only radios with an RDS feature can receive.  Between 1994 and 1996, the number of RDS radio stations in Verdland increased from 250 to 600.  However, since the number of RDS-equipped radios in Verdland was about the same in 1996 as in 1994, the number of Verdlanders receiving the special program information probably did not increase significantly.
Which of the following is an assumption on which the argument depends?
(A) Few if any of the RDS radio stations that began broadcasting in Verdland after 1994 broadcast to people with RDS-equipped radios living in areas not previously reached by RDS stations.
(B) In 1996 most Verdlanders who lived within the listening area of an RDS station already had a radio equipped to receive RDS.
(C) Equipping a radio station with RDS technology does not decrease the station's listening area.
(D) In 1996 Verdlanders who did not own radios equipped to receive RDS could not receive any programming from the RDS radio stations that began broadcasting in Verdland after 1994.
(E) The RDS radio stations in Verdland in 1996 did not all offer the same type of programming.
本题答案为A。注意A选项的few和not都表示否定，双重否定表肯定，即“1994年时RDS station已经覆盖了所有地区”

kuaijizu

When an airplane is taken out of service for maintenance, it is often repainted as well, and during the repainting no other maintenance work can be done on the plane.  In order to reduce maintenance time, airline officials are considering using a new nontoxic plastic film instead of paint.  The film takes just as long to apply as paint does, but many other maintenance tasks can be carried out at the same time.
Which of the following, if true, is further evidence that using the film will help the airline officials achieve their goal?
(A) Unlike paint, the film gives a milky tone to certain colors.
(B) At the end of its useful life, the film can be removed much more quickly than paint can.
(C) The film can be applied only by technicians who have received special training.
(D) The metal exteriors of airplanes have to be protected from high temperatures and caustic chemicals such as exhaust gases.
(E) Even at speeds considerably higher than the normal speed of a passenger jet, the film remains securely attached.
答案为B。注意本题问题讨论的是实现goal，根据原文，该goal一定是reduce maintenance time，其他问题一律不考虑。

kuaijizu

The Calex Telecommunications Company is planning to introduce cellular telephone service into isolated coastal areas of Caladia, a move which will require considerable investment.  However, the only significant economic activity in these areas is small-scale coffee farming, and none of the coffee farmers make enough money to afford the monthly service fees that Calex would have to charge to make a profit.  Nevertheless, Calex contends that making the service available to these farmers will be profitable.
Which of the following, if true, provides the strongest support for Calex's contention?
(A) Currently, Caladian coffee farmers are forced to sell their coffee to local buyers at whatever price those buyers choose to pay because the farmers are unable to remain in contact with outside buyers who generally offer higher prices.
(B) In the coastal areas of Caladia where Calex proposes to introduce cellular telephone service, there is currently no fixed-line telephone service because fixed-line companies do not believe that they could recoup their investment.
(C) A cellular telephone company can break even with a considerably smaller number of subscribers than a fixed-line company can, even in areas such as the Caladian coast, where there is no difficult terrain to drive up the costs of installing fixed lines.
(D) Calex bases its monthly fees for cellular telephone service in a given region partly on the cost of installing the necessary equipment to provide the service there.
(E) Calex has for years made a profit on cellular telephone service in Caladia's capital city, which is not far from the coastal region.
答案为A。A选项说明未来引入电话后，农民收入会增加，并非是反驳原文倒数第二句话说的“目前农民付不起手机费”。