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标题: TT2 math14 [打印本页]

作者: amyding85 时间: 2006-8-31 00:36
标题: TT2 math14

Q14:

C_(m,n) = m! / [(m-n)! n!] for nonnegative integers m and n, m ³ n. If C_(5,3) = C_(5,x) and x ¹ 3, what is the value of x?

A. 0

B. 1

C. 2

D. 4

E. 5

Answer: c

不明白啥意思啊？没找到讨论贴

作者: lovetiky 时间: 2006-8-31 01:59

C(m,n)=m!/[(m-n)!n!]

C(5,3)=5!/[(5-3)!3!]=5!/[(2)!3!]

=C(5,2)=5!/[(5-2)!2!]=5!/[(3)!2!]

作者: amyding85 时间: 2006-8-31 16:57

thanks a lot

作者: Amber789 时间: 2008-7-15 09:46
集体的智慧威力无比啊.

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