两题GWD 实在找不到答案 求NN解答

caijilei

GWD9-Q20:

	Favorable	Unfavorable	Not Sure
Candidate M	40	20	40
Candidate N	30	35	35

The table above shows the results of a survey of 100 voters each responded “favorable” or “unfavorable” or “not sure” when asked about their impressions of candidate M and of candidate N.  What was the number of voters who responded “favorable” for both candidates?

(1)   The number of voters who did not respond “favorable” for either candidate was 40.

(2)   The number of voters who responded “unfavorable” for both candidates was 10.

                  

A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.

B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.

C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.

D. EACH statement ALONE is sufficient.

E. Statements (1) and (2) TOGETHER are NOT sufficient.

Answer:

这题答案说是A 但是知道A中的信息根本不能知道有哪些人选not sure啊 求解

GWD9-36

If x, y, and k are positive numbers such that [x/(x+y)](10) +[x/(x+y)] (20) = k and if x < y, which of thefollowing could be the value of k?

A.   10

B.    12

C.    15

D.   18

E.    30

两个空格里面都是x/(x+y) 谢大家！

caijilei

lucyhou 发表于 2013-8-13 23:20
第二个答案是a吗？

第二题答案是E

caijilei

lhz910216 发表于 2013-8-13 23:00
1
条件说有40个人呢既没有给M好评，有没有给N好评，然后看表
M对应的差评和not sure加起来是60，那这60人里 ...

发现把题目打错了 应该是 [x/(x+y)](10) +[y/(x+y)] (20) = k 然后我觉得可以变成(10x+20y)/(x+y)=k 然后可以进一步化为10x+20y=k(x+y) 求解这个想法对不对的 为什么你觉得把x+y凑成5就可以约去啊