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Moderate

Factorial Simplification

ACTMAT-GALJNK

The expression $n!$ (read "n factorial") is the product of the integer $n (n > 0)$, times one less than $n$, times two less than $n$, etc., times 1. In other words:

$$ n!=n(n-1)(n-2)(n-3)...(3)(2)(1) $$

Which of the following is equivalent to:

$$ \frac { n! }{ (n-2)! } $$

A

$ \cfrac { n }{ (n-2) } $

B

$ \cfrac { n(n-1) }{ 2 } $

C

$2n-1$

D

$n(n-1)$

E

$2n(n-1)$