If a committee of 3 people is to be selected from among 5 married couples so that the committee does not include two people who are married to each other, how many such committees are possible?
A.20
B.40
C.50
D.80
E.120
这一题我选了20,但是错的。我对这一类型的题总是迷糊,不知道该拿他怎麽办。哪一位可以在这一类方面给我讲解讲解,可以让我更清楚一些。我又阅读过一些关于permutation and combination 的解释,但是我觉得没有多大用在做这类题时。不知道那位可以指点我一下。万分感激!!!