Let XXX follow a geometric distribution P(X=k)=p(1−p)k−1P(X=k) = p(1-p)^{k-1}P(X=k)=p(1−p)k−1 for k=1,2,…k=1, 2, \dotsk=1,2,…. What is E[X]E[X]E[X]?
ppp
1/p1/p1/p
p−1p-1p−1
1−p1-p1−p