Question

If ${{}^{n}C}_{12}$ =${{}^{n}C}_8$ then $n$ is equal to

• A. 26
• B. 12
• C. 6
• D. 20

Answer 1

Answer: (D)

We know that.
If ${}^n{C}_x={}^n{C}_y$, then
(i) $x=y$
(ii) $x+y=n$
$\therefore {}^n{C}_{12}={}^n{C}_8$
$\Rightarrow n=12+8=20$