Answer
$6$
Work Step by Step
Use the formula $P(n,r)=\dfrac{n!}{(n-r)!}$.
Here we have $n=8$ and $r=2$:
Substitute these values into the formula above to obtain:
$P(3,2)=\dfrac{3!}{(3-2)!}\\$
$P(3,2)=\dfrac{3!}{1!}\\$
$P(3,2)=\dfrac{3*2*1}{1}$
Cancel out the common factors to obtain:
$P(8, 2) = 3\cdot2 = 6$