Answer
190
Work Step by Step
$\frac{20!}{2! 18!}$
Try to reduce the fraction before performing the multiplications.
We can express 20! as
20! = 20*19*18!.
We can divide both the numerator and the denominator by the common factor, 18!.
$\frac{20!}{2! 18!}$ = $\frac{ 20*19*18!}{2*1*18!}$ = $\frac{20*19}{2}$= 190
