Q. What is the value of $^{n} C_{n}$ ?

7546 193 Permutations and Combinations Report Error

A

0

23%

B

$\infty$

14%

C

r

9%

D

1

55%

Solution:

$^{n} C_{n} = \frac{n !}{n ! ( n - n ) !} = \frac{n !}{n ! 0 !}$
$= \frac{n !}{n !} = 1$