这是原题么？还是翻译的版本?

来源: 我稀饭捣乱 于 2007-01-24 08:22:23 [] [旧帖] [给我悄悄话] 阅读数 : (293 bytes)

看到你写的答案，会想到这个, 不过也是猜得
6^5 = 7776
Variations (without repetition): n!/(n-k)!
Variations with repetition: nk

Combinations (without repetition): n!/k!(n-k)! or (n above k)
Combinations with repetition: (n+k-1)!/k!(n+k-1-k)! or (n+k-1 above k)



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