1.

Prove that (nC0 + nC1) (nC1 + nC2)(nC2 + nC3)......(nCn-1 + nCn)  = \(\frac{(n+1)^n}{n!}\)(nC1.nC2.nC3......nCn)

Answer»

(nC0 + nC1) (nC1 + nC2)(nC2 + nC3)......(nCn-1 + nCn)

= n+1C1 + n+1C2 + n+1C3....n+1Cn

 = \(\frac{n+1}1\times\frac{(n+1)n}2\times\frac{(n+1)(n)(n-1)}{3!}....\times\frac{(n+1)}{1!}\)

 = (n+1)n\((\frac{n}{n}\times\frac{n(n-1)}{2(n-1)}\times\frac{n(n-1)(n-2)}{3!(n-2)}....\times1)\)

= (n + 1)n x \(\frac{1}{n(n-1)(n-2)....}\times(n\times\frac{n(n-1)}2\times\frac{n(n-1)(n-2)}{3!}\times....\times1)\) 

 = \(\frac{(n+1)^n}{n!}\)(nC1.nC2.nC3......nCn)

Hence Proved



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