Question

The sum of the series 1⋅2⋅3 + 2⋅3⋅4 + 3⋅4⋅5 +… to n terms is

(A)  n(n + 1)(n + 2)(n + 3)/5

(B)  n(n + 1)(n + 2)(n + 3)/4

(C)  n(n + 1)(n + 2)(3n + 13)/12

(D)  None of these

Answer 1

Correct option  (B)  n(n + 1)(n + 2)(n + 3)/4

General term of series = r(r + 1)(r + 2)

Sum of the series