Q11: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?

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.
Among subscribers to Systems, the proportion who are under age thirty-five was considerably lower last year than it is now.
Most merchandise orders placed in response to advertisements in Systems last year were placed by Systems subscribers over age thirty-five.

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

答案E，可是题干很绕，我看不懂意思，谁帮我解释一下？

1."在所有的购买的商品中,其中30%是那些35岁以下的定阅 杂志的年轻人根具广告而购买的"

2."通过杂志广告而卖出的商品中,大部份是卖给35岁以下的年轻人".

1+2得到的就是"定阅 杂志且购买了商品的那些人大部份是35岁以下的年轻人且只占在所有的购买的商品中的30%".

"那70%是由非定阅 杂志的人买的" -----> E

i see,thanks !!!!!!!!!!!!