Binomial RV: many biased coins.
p - probability of heads in one toss. N - number of tosses.
E[X] = (N)(p) E[Y] = N - (N)(p) = N (1 - p)
Y seems to be just like X, except with probability (1 - p).
Conclusion: Y is a binomial RV with parameters N and (1 - p).
