回复:数学题求救,先谢了

来源: 2012-04-12 20:22:25 [旧帖] [给我悄悄话] 本文已被阅读:

1. (10C1)x(9C3)x7!/4!x9/10=158760

2. (10C2)x(8C3)x7!/2!/2!x9/10=2857680