ChaseDream
搜索
返回列表 发新帖
00:00:00

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?

正确答案: E

相关帖子

更多...

更多相关帖子

524

帖子

15

好友

4712

积分

ChaseDream

注册时间
2003-03-17
精华
8
解析
查看: 3739|回复: 2
打印 上一主题 下一主题

问一道旧prep12题

[复制链接]
跳转到指定楼层
楼主
发表于 2010-7-22 21:59:14 | 只看该作者 回帖奖励 |倒序浏览 |阅读模式
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.

这个题说,subscribers中间有30%的人是under 35,而总人中有most也就是大于50%的人是under 35,那不是说明不是subscribers 又place merchandise orders 有大于30%的人是under 35 的吗?为什么题目答案e说没定杂志的人中place orders of merchandise 的人多?这有什么关系啊?不理解,请大牛们给指点指点
收藏收藏 收藏收藏
沙发
发表于 2010-7-22 23:35:35 | 只看该作者
我觉得吧,你可以用韦恩图想想
subscribers & under age thirty-five = 30% A (假设A=subscriber)
under age thirty-five >=50% B (假设B=total)
B>A
所以30% A < 50% B
所以 一定有不是subscribers 下order的。E里面没有说多,只是说有这样的人。
板凳
 楼主| 发表于 2010-7-23 11:37:05 | 只看该作者
啊,原来是这样,谢谢谢谢
您需要登录后才可以回帖 登录 | 立即注册

Mark一下! 看一下! 顶楼主! 感谢分享! 快速回复:

手机版|ChaseDream|GMT+8, 2024-11-30 17:34
京公网安备11010202008513号 京ICP证101109号 京ICP备12012021号

ChaseDream 论坛

© 2003-2023 ChaseDream.com. All Rights Reserved.

返回顶部