Answer
42
Work Step by Step
Use the formula of permutation: $_{n}$P$_{r}$=$\frac{n!}{(n-r)!}$. Plug in 7 for N and 2 for R:
$_{n}$P$_{r}$=$\frac{n!}{(n-r)!}$
$_{7}$P$_{2}$=$\frac{7!}{(7-2)!}$ -simplify like terms-
$_{7}$P$_{2}$=$\frac{7!}{5!}$ -write using factorial-
$_{7}$P$_{2}$=$\frac{7*6*5*4*3*2*1}{5*4*3*2*1}$ -simplify-
$_{7}$P$_{2}$=42
