Let Z1,Z2,Z3,...Zi be iid bernoulli random variables. Let Y be the first Zi to be 1. Calculate E(Y). I know it's a geometric distribution, then i write, E(Y)=∑ 1 x p x q^(y-1). Z1, Z2 Z3... Zi is a bernoulli distribution, so I think the value of Y to be the fisrt success is "1". however, i just wondering the value of Y is the value of Z1, Z2, Z3... ( 0, 1) or the number of trials to get the first success.. I need an explanation. Thx a lot..