prep-1-12 ,没头绪

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E)这种题如何解的思路?

ding, need help. no body here?

我的理解

A:杂志去年所有购物订单的30%来自小于35岁的杂志订阅者

B:大部分的购物订单（应远大于30%）来自小于35岁的读者。

30%与大部分之间体现的关系就是答案：实际购物的人中大部分并不是杂志的订阅者。

A: 去年，在所有来自杂志订户的订货单中，30%订货单来自于35岁以下的订户。

即：30%*买东西的订户属于35岁以下——70%买东西的订户属于35岁以上

B: 大多数的订单，来自于35岁以下的人群。

即：大部分买东西的人属于35岁以下。

因此，集合{大部分买东西的人}与集合{70%买东西的订户}不存在交集——大部分买东西的人不属于大部分订户——大部分买东西的人不是订户。

I guess this is the line of reasoning. Kinda like a math problem.

差异在于in systems:

most orders...in systems ..under 35

30% orders subscribers under 35

--> many orders...in systems not subscribers （因为30%相对占少数)

(A) 討論主題並非35歲以上者...且出現"never" 極端詞, 排除

(B) irrelevant

(C) 與題目矛盾

(D) Irrelevant

(E) (1)雜誌訂戶中只有 30% 訂購, 且均為35歲以下者(2)大部分訂單來自35歲以下者; ==> 大部分的訂購者並非雜制訂戶 

故選E