作者catspace (柏拉圖的永恆...)
看板GMAT
標題Re: [問題] Please help a "vegetable bird" like me
時間Fri Sep 12 21:03:25 2008
※ 引述《RainySunDay (Heart fly)》之銘言：
: 1.How many different 6-letter sequences are there that consist of 1 A, 2 B's,
: and 3 C's?
: A:60
不就是不盡相異物的排列嗎?
6!
----- = 60 #
2!3!
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1F：推 RainySunDay:Thanks, but more explanation could be better,ha ha 09/13 01:45
2F：推 windton:在統計學裡，這有點像是公式的東西吧，可以背一下^^ 09/13 02:36