谁给我讲下二维表的问题，不理解啊

ossan · 发表于 2011-3-16 14:02:41

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.[l6]
(2) In the survey, 288 men said that they considered engaging in research an essential goal.
【解】：A
1）破题：
A）理解的关键：见批注
B）破题：这是一个标准的二维表问题
2）思路：见下表
  E   E取非   T
F   50%x;700      X
M   36*(1400-x);288      1400-x
T   *42%      1400
【NOTE】：黑色字为题干已知；绿色字为条件1已知；红色字为条件2已知。

ossan · 发表于 2011-3-16 14:08:03

这类题大家是一个个条件看呢还是像解法列表？

ossan · 发表于 2011-3-16 14:18:18

3、Each employee of Company Z is an employee of either Division X or Division Y, but not both. If each division has some part-time employees, is the retio of the number of full-time employees to the number of part-time employees greater for Division X than for Company Z?

(1) The ratio of the number of full-time employees to the number of part-time employees is less for Division X than for Company Z.
(2) More than half of the full-time employees of Company Z are comployees of Division X, and more than half of the part-time employees of Company Z are employees of Division Y.
比如这题

nightingale · 发表于 2011-3-17 16:28:46

哇，这两题昨天模考都碰到了。

没研究过几天数学，不知道什么是二维表，不过可以讲一下这两道题的解法：

首先，所有的Data Sufficiency的题都应该每个选项单独看的，如果两个单独看都不能得出结论才合起来看。

第一题A选项很明显，设women是x人，men就是1400-x，那么用第一个条件表示就是36%*(1400-x)+50%*x=1400*42%，解出x=600；用第二个条件算不出，所以最后选A。

第二题稍微麻烦一点，没有明确数字。LZ的题目写错了吧，第一个条件应该是less for Division Y than for Company Z?
先要知道一个问题，就是(Fx+Fy)/(Px+Py)肯定介于Fx/Px和Fy/Py之间。
看第一个条件，因为Fy/Py<(Fx+Fy)/(Px+Py)，因此Fx/Px>(Fx+Fy)/(Px+Py)=Fz/Pz。
看第二个条件，可以知道Fx>Fy, Px<

y,所以Fx/Px>Fy/Py，因此Fx/Px>(Fx+Fy)/(Px+Py)=Fz/Pz。
所以最后选D。

谁给我讲下二维表的问题，不理解啊

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