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标题: PREP上的题目，请教各位。。。 [打印本页]

作者: Sophin 时间: 2011-1-24 21:49
标题: PREP上的题目，请教各位。。。

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.

答案是E，请教各位高人指点一下，我对这种题目一点办法都没有，答案看来看去头就昏了。请给出一个解题思路，非常感谢！！！！！

作者: vinica 时间: 2011-1-25 21:40
主要就是分清楚一点，第一句话说的是有30%的订单是来自于该杂志的订阅者（35岁以下的），而第二句话说的是大部分的（可以理解为大于50%）订单都是来自于35岁以下的人（包括该杂志的订阅者和非订阅者），这样就可以知道非订阅者的人数肯定是大于订阅者人数的，这样总的收到订单的百分比才会提升。也不知道这样说请不清楚，我个人的想法~但愿有帮助哇~

作者: Sophin 时间: 2011-1-26 11:44
谢谢楼上的回复，有点道理的。。。

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