ChaseDream

标题: GWD-26-37 总是求助 ~ [打印本页]

作者: songyang0121    时间: 2009-4-1 22:22
标题: GWD-26-37 总是求助 ~

Q37:

In a meeting of 3 representatives from each of 6 different companies, each person shook hands with every person not from his or her own company.  If the representatives did not shake hands with people from their own company, how many handshakes took place?

 

A.     45

B.      135

C.      144

D.     270

E.      288

答案是B

一点思路没有 求助~


作者: zzhGGforever    时间: 2009-4-3 00:30

可以用排除法。先将所有可能的握手组合算出,C(18,2)=153,再减去同一个公司的握手C(3,2),因为6个公司,共6*3=18种握手是公司内部滴。153-18=135


作者: songyang0121    时间: 2009-5-22 18:25

非常感谢~






欢迎光临 ChaseDream (https://forum.chasedream.com/) Powered by Discuz! X3.3