Question

The sum $\frac{3}{1^{2}}+\frac{5}{1^{2}+2^{2}}+\frac{7}{1^{2}+2^{2}+3^{2}}+......$ upto 11-terms is:
(a) $\frac{7}{2}$
(b) $\frac{11}{4}$
(c) $\frac{11}{2}$
(d) $\frac{60}{11}$

Answer 1

your answer is (a) option