Consider a sequence of independent repeated bernoulli

Question

Consider a sequence of independent repeated Bernoulli trials in which the probability of success on any trial is p = 5/16

(i) Let S_n be the number of trials required to achieve the nth success. Find E[S_n] and Var [S_n].

(ii) Let T_n be the number of failures encountered before the nth success is achieved. Find .E[T_n] and Var [T_n].