请教Prep12

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.

一项对Systems 杂志的订阅者的调查显示：30%由订阅者下的对于杂志上刊登广告的产品的订单是由35岁以下的订阅者做出的

一项对S杂志的广告的调查显示：大多数看了S杂志上的广告以后下的订单是由35岁一下的人群下的

大多数订单是由35岁以下人群下的，那么很少一部分是由35岁或以上的人群下的（这其中包括了杂志订阅又下订单者的70%），这也就说明第一个条件中的人比这很少的一部分的比例还少，这样的话那么其他构成大部分下订单的群体就不是杂志的订阅者了。

楼主好好想想

同时成立，有2种可能：

1 回复广告的大部分是
        35以下的少数人重复很多次购买导致35一下总次数高，因此35岁以上的人数虽然多但是每个只买一次导致总数少

2 回复广告的大多是35以下的非订阅者

(E) Last year many people who placed orders for merchandise in response to advertisements in Systems were not subscribers to the magazine.