这题明显有问题呀！？

frankzhiwei

165.16466-!-item-!-187;#058&010795

Of the 1,400 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 essential goal.



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

--------------------------------------------------------------------------------------------------------------------------------------------------------【答案】A



【思路】(1) total（1400) x 42/100=588(參加人數） , 588 x women比例（50 / 100)=參加女人的比例 , 充份

(2)原題問surveyed werer women , 包含 engage 和 not engage , so we only can get engage women , 不充份

大家看解释（1），算出588是所有人里面认为research essential的，可是后面却继续乘50%说是女的人数，可根本就是两个部分呀~这么说吧：
开头说那42%认为research essential的人是来自1400里的，其中包括Men 和 Women，这两个多少我们不知道！ 所以后面说的那50%是W的50%，而不是42%里面的（这里包括M,W）50%呀，大家怎么说？

frankzhiwei

谢谢呀！没想到就那儿弄来弄去就解出来了~

richardyam15

我同意你说法，选c才行

大地上的树

165.16466-!-item-!-187;#058&010795

Of the 1,400 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 essential goal.



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

--------------------------------------------------------------------------------------------------------------------------------------------------------【答案】A



【思路】(1) total（1400) x 42/100=588(參加人數） , 588 x women比例（50 / 100)=參加女人的比例 , 充份

(2)原題問surveyed werer women , 包含 engage 和 not engage , so we only can get engage women , 不充份

大家看解释（1），算出588是所有人里面认为research essential的，可是后面却继续乘50%说是女的人数，可根本就是两个部分呀~这么说吧：
开头说那42%认为research essential的人是来自1400里的，其中包括Men 和 Women，这两个多少我们不知道！ 所以后面说的那50%是W的50%，而不是42%里面的（这里包括M,W）50%呀，大家怎么说？

-- by 会员 frankzhiwei (2010/9/24 12:29:31)

1是可以推出来的，这1400人不是男的就是女的（估计不在泰国，哈哈）设男的为x，那么女的就是1400-x，那么
1400*42%=x*36%+（1400-x）*50%算出x。
2只能算出有多少人不支持research essential的观点，但是算不出男女的比例，所以不充分。

fuxiaoyang0512

这就是2部分，是两个式子组成的二元一次方程组
设men的人数是x，women的人数是y
36%x+50y=1400*42%
（1-36%）x+（1-50%）y=1400*（1-42%）
可以求出x和y来