a.(1/33)*sigma(n=1 to n=16) {(4*n^4)/((4*n^2)-1)} = ?b.sigma(k=0 to k=n){(2^k)*(2nCk)} = ?

Dear student,

Make use of these important concepts,

(a)  Number of combinations of ‘n’ different things taken ‘r’ at a time, when ‘p’ particular things are always included = ^n-pC_r-p.

(b)  Number of combination of ‘n’ different things, taken ‘r’ at a time, when ‘p’ particular things are always to be excluded = ^n-pC_r

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All the best.

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Sagar Singh

B.Tech, IIT Delhi