请教大家一提PREP

yoyozjm1228

 

PREP 1 ----

43.   5768-!-item-!-187;#058&004705

A committee of three people is to be chosen from four married couples.  What is the number of different committees that can be chosen if two people who are married to each other cannot both serve on the committee?

 

 

(A)  16

(B)  24

(C)  26

(D)  30

(E)  32

yoyozjm1228

谢谢楼上的解释, 我明白了!

3smoviesalon

或者从正面像是

c43*c21*c21*c21

yoyozjm1228

谢谢你的解答, 但是另外一位XDJM的解答是

首先从4对couples中选三对。再从三对中任选。2^3

两个解答有什么分别...

forgetviviva

这题我会做，

任选三个 - 出现一对的情况 （C41 是一对，C61是从剩余6人中任选1人）

C83 - C41*C61 = 32