Prep数学题

charlottecheng · 发表于 2010-4-26 18:28:57

Sets A, B, and Chave some elements in common. If 16elements are in both A and B, 17 elements are in both A and C, and 18 elementsare in both B and C, how many elements do all three of the sets A, B, and Chave in common?

(1) Of the 16elements that are in both A and B, 9 elements are also in C.

(2) A has 25elements, B has 30 elements, and C has 35 elements.

条件1是sufficient的，条件2，如果不用列举法，怎样得出sufficient or not?

yamyam0806 · 发表于 2011-8-20 23:08:04

条件2的我也很疑惑乍眼看感觉答案能斗出来可实际上是不可以的吧？有没有人来肯定答复一下呢？
我选的D是错的

xiaoyaopili · 发表于 2011-8-20 23:39:20

设都相交的是x，则按条件二得：
A16+17-x<25即x>8
B16+18-x<30即x>4
C17+18-x<35即x>0
无法求得x

Prep数学题

所属分类: GMAT考试

正在浏览此版块的会员 ()

浏览过的版块