请教LSAT-17-3-12,LSAT-17-3-20

albert

12. Some of the most prosperous nations in the world have experienced a pronounced drop in national savings rates-the percentage of after-tax income an average household saves. This trend will undoubtedly continue if the average age of these nations' populations continues to rise, since older people have fewer reasons to save than do younger people.
Which one of the following indicates an error in the reasoning leading to the prediction above?
(A) It fail to specify the many reasons younger people have for saving money, and it fails to identify which of those reasons in the strongest.
(B) It assumes that a negative savings rate-the result of the average household's spending all of its after-tax income as well as some of its existing savings-cannot ever come about in any nation.
(C) It fails to cite statistics showing that the average age of the population of certain nations is rising.
(D) It only takes into account the comparative number of reasons older and younger people, respectively, have for saving, and not the comparative strength of those reasons.
(E) It uses after-tax income as the base for computing the national savings rate without establishing by argument that after-tax income is a more appropriate base than before-tax income.
Answer: D

20. Most people in the United States view neither big nor small business as particularly efficient or dynamic and regard both as providing consumers with fairly priced goods and services. However, most people consistently perceive small business as a force for good in society whereas big business is perceived as socially responsible only in times of prosperity.
The statements above, if true would provide the strongest support for which one of the following hypotheses?
(A) Most people in the United States give little thought to the value of business to society.
(B) If big business were more efficient, it would be perceived more favorably by the public generally.
(C) If small business were regarded as being more dynamic, it too, would receive strongly favorable ratings only in times of general prosperity.
(D) Even if people did not regard big business as providing consumers with value for their money, they would still regard it as socially responsible in times of general prosperity.
(E) Many people in the United States regard the social responsibility of big business as extending beyond providing consumers with fairly priced goods and services.
Answer: E


23. 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.
Answer: C 我知道C没问题，但是 a,e能作为支持吗？
谢谢各位!

siebel

都是后来想清楚的，请指正。

以下是引用albert在2003-5-20 23:12:00的发言：
12. Some of the most prosperous nations in the world have experienced a pronounced drop in national savings rates-the percentage of after-tax income an average household saves. This trend will undoubtedly continue if the average age of these nations' populations continues to rise, since older people have fewer reasons to save than do younger people.

比较的本质，是原因导致的结果，而不是原因数量的多少。老头有1万条存钱的理由但只有1块钱去存，小伙只有一条理由，却存了1万块。

20. Most people in the United States view neither big nor small business as particularly efficient or dynamic and regard both as providing consumers with fairly priced goods and services. However, most people consistently perceive small business as a force for good in society whereas big business is perceived as socially responsible only in times of prosperity.
The statements above, if true would provide the strongest support for which one of the following hypotheses?
(A) Most people in the United States give little thought to the value of business to society.
(B) If big business were more efficient, it would be perceived more favorably by the public generally.
(C) If small business were regarded as being more dynamic, it too, would receive strongly favorable ratings only in times of general prosperity.
(D) Even if people did not regard big business as providing consumers with value for their money, they would still regard it as socially responsible in times of general prosperity.
(E) Many people in the United States regard the social responsibility of big business as extending beyond providing consumers with fairly priced goods and services.
Answer: E

大公司性价比不好是事实。有social responsibility也是事实。二者无关。

23. 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.
(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.

也是一个mindfree提到的slope的问题。原文的slope是所有人，AE只包含现有读者，既无法加强，也无法削弱。

mindfree

1. 此题首先用排除法排除ABCE. D对是因为原文指出rate有一个pronouced drop. 然后说因为average age continues to rise,这个trend会继续. 这里将age作为原因,导致pronouced rate drop. D指出其问题是此原因的影响力是否能造成pronouced drop, 即不能排除可能有其它因素共同作用.

2. 讨论过.

3. A错在不能说明收到survey的人群有代表性, E是削弱, 通过计算可以得到实际支持format change的比例小于50%.

albert

谢谢siebel兄。
12，23题明白了。
20题还不明白。