Each week Manhattan GMAT posts a GMAT question on our blog and follows up with the answer the next day. Are you up for the challenge?
If two integers are chosen at random out of the set {2, 5, 7, 8}, what is the probability that their product will be of the form a2 – b2, where a and b are both positive integers?
(A) 2/3
(B) 1/2
(C) 1/3
(D) 1/4
(E) 1/6