Hello,

Could you please help me about the following question :

Suppose X is a discrete random variable on the set of positive integers such that for each positive integer n, the probability that X = n is 1/(2^n). If Y is a random variable with the same probability distribution and X and Y are independent, what is the probability that the value of at least one of the variables X and Y is greater than 3?

(A) 1/64

(B) 15/64

(C) 1/4

(D) 3/8

(E) 4/9

The answer is B. Thank you all.