Answers

2015-11-25T12:06:59+08:00
C. 1

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

So if n and r are the same number, we can say that:

C(n,n) = n!/[(n!)(n-n)!]
C(n,n) = n!/[(n!)(0!)]
C(n,n) = n!/n!
C(n,n) = 1



 - D.E.
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