question_answer

A variable x takes the values 0, 1, 2, ...n with frequencies proportional to\[qn\,,\,n{{C}_{1}}.q{{n}^{-1}}.p\], \[n{{C}_{2}}\,qn{{~}^{-2}}.{{p}^{2}}....\]respectively and \[\text{p }+\text{ q }=\text{ 1};\]then the mean is

A) \[\left( \text{n}+\text{q} \right)\text{p}\]         

B)         \[\left( \text{n}+\text{p} \right)\text{n}\]

C)  np                           

D)         \[\text{n}+\text{pq}\]