求解-math (陈向东)

wanqiu.beijing

A certain club has 8 members, including Harry. One of the 8 members is to be chosen at random to be the president, one of the remaining 7 members is to be chosen at random to be the secretary, and one of the remaining 6 members is to be chosen at random to be the treasurer. What is the probability tht Harry will be either the member chosen to be the secretary or the  member chosen to be the treasurer?
各位大侠，请问这题怎么解答啊，小弟跪谢了

JoshLian

What is the correct answer?  My answer is 7/8 x (1/7+6/7x1/6) = 1/4.

wanqiu.beijing

JoshLian 发表于 2017-6-14 04:36
What is the correct answer?  My answer is 7/8 x (1/7+6/7x1/6) = 1/4.

谢谢您的回复，答案就是1/4, GMAT对我来说实在太难了，这道题昨晚我没想明白，今晚才恍然大悟，谢谢你的帮助