E
Editor
Sep 18, 2022
$^{n}P_{r}+^{n}C_{r}$=
Difficulty: Easy
A:
$\frac{1}{r!}$
B:
$\frac{n!}{r!}$
C:
n!r!
D:
$\frac{1}{n!}$
Report issue
ID: 63273dbaca83163ac3a12473