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 p and n are positive integers, with p > n, what is the average of n consecutive multiples of p (starting with p), less the average of p consecutive multiples of n (starting with n)?
(A) (p + n)/2
(B) (p – n)/2
(C) p + n
(D) p – n
(E) p2 – n2