If p.m.f. of a d.r.v. X is P(X = = \(\frac{x}{n(n+1)}\), for x = 1, 2, 3, ……, n and = 0, otherwise, then E(=
A. \(\frac{n}{1}+\frac{1}{2}\)
B. \(\frac{n}{3}+\frac{1}{6}\)
C. \(\frac{n}{2}+\frac{1}{5}\)
D. \(\frac{n}{1}+\frac{1}{3}\)
Answer:B
If p.m.f. of a d.r.v. X is P(X = = \(\frac{x}{n(n+1)}\), for x = 1, 2, 3, ……, n and = 0, otherwise, then E(=
A. \(\frac{n}{1}+\frac{1}{2}\) B. \(\frac{n}{3}+\frac{1}{6}\) C. \(\frac{n}{2}+\frac{1}{5}\) D. \(\frac{n}{1}+\frac{1}{3}\)