请教一道PREP中的一道DS,请牛牛们指点

kellynos

Of the 1400 college teachers surveyed, 42 percent said that they considered engaging in research an essential goal.How many of the college teachers surveyed were women.

1>In the survey, 36 percent of the men and 50 percent of the women said that they considered engaging in research an eseential goal.

2>In the survey, 288men said that they considered engaging in research an essential goal.

答案是A,为什么答案不是D呢?

其实1400乘以百分之42就是所有参加调查的老师减去条件2中的288个男老师,剩下的不就是女老师的人数吗?

答案为什么会是A呢?

grantchao

GG看错题了，是1400人参与了调查，其中42%的说他（她）们以科研为目标。问参与调查的女教师有多少人？

1〉设男教师X人，女教师Y人，可得方程组 X*36%+Y*50%=1400*42%

                                      X+Y=1400,可求出Y

2〉推不出Y，只能推出Y中有多少人以科研为目标，而题目求得是Y.

[此贴子已经被作者于2009-3-21 12:44:49编辑过]

kellynos

不好意思,还是不懂.

大胖

其实1400乘以百分之42就是所有参加调查的老师减去条件2中的288个男老师,剩下的不就是女老师的人数吗?  两者相减
        应该是女老师 who considered engaging in research an essential goal的人数

zqlflw

同求啊同求啊

cnrnld

好象美国现在对性别的看法有
MALE, FEMAIL, NEUTRAL,以及生理男但感知女、生理女但感知男一共五种。

elsieb

楼上，楼歪了。。哈哈