Question

If ${{}^{n}C}_8={{}^{n}C}_2$ find the value of $n$.

Answer 1

It is known that, when ${}^n{C}_a={}^n{C}_b$, then,

$n=a+b$

Now, as it is given that ${}^n{C}_8={}^n{C}_2$, then,

$n=8+2$

$n=10$