Answer
$151,200$
Work Step by Step
See review summary:
b. Factorial Notation
$n!=n(n-1)(n-2)\cdots(3)(2)(1) $ and $0!=1 $(by definition)
( It follows that $n!=n(n-1)!$ )
c. Permutations Formula$ \displaystyle \quad {}_{n}P_{r}=\frac{n!}{(n-r)!}$
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${}_{10}P_{6}=\displaystyle \frac{10!}{(10-6)!}=\frac{10!}{4!}\qquad $... apply $n!=n(n-1)!$
$=\displaystyle \frac{10\times 9!}{4!}$
$=\displaystyle \frac{10\times 9\times 8\times 7\times 6\times 5\times 4!}{4!}\qquad$
... reduce the fraction (divide with $\displaystyle \frac{4!}{4!}$)
=$10\times 9\times 8\times 7\times 6\times 5$
= $151,200$
