觉得是：（C(M-1,K-1)C(N-1,K-2)+C(N-1,K-1)C(M-1,K-2)）/C(M+N,M)

来源: wxcfan123 于 2013-01-05 09:57:21 [旧帖] [给我悄悄话] 本文已被阅读：次

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觉得是：（C(M-1,K-1)*C(N-1,K-2)+C(N-1,K-1)*C(M-1,K-2)）/C(M+N,M)