If p and n are positive integers and p > n, what is the remainder when p^2 – n^2

If p and n are positive integers and p > n, what is the remainder when p^2 – n^2

If p and n are positive integers and p > n, what is the remainder when p^2 – n^2 is divided by 15? GMAT Explanation

If p and n are positive integers and p > n, what is the remainder when p^2 – n^2 is divided by 15?

(1) The remainder when p + n is divided by 5 is 1.
(2) The remainder when p – n is divided by 3 is 1.