Question

If nC3 = nC9 then nC2 =​

Answer 1

Step-by-step explanation:

nC3=n!/3!(n-3)!

nC9=n!/9!(n-9)!

To find nC2

nC2 = n!/2!(n-2)!

We can write nC3 as

nC3= n!/(3×2!)(n-3)(n-2)!

now nC3=nC9

n!/(3×2!)(n-3)(n-2)!=nC9

n!/2!(n-2)!×(3)(n-3)=nC9

nC2/3×(n-3)=nC9

Ans nC2=n(n-3)nC9