If the sum of two positive integers is 20 and the difference of their squares is 40, what is the product of the two integers?	Options:
A) 108	B) 99	C) 128	D) 135	E) 143

Rationale: "let the 2 positive numbers x and y x + y = 20 - - 1 x ^ 2 - y ^ 2 = 40 = > ( x + y ) ( x - y ) = 40 - - 2 using equation 1 in 2 , we get = > x - y = 2 - - 3 solving equation 1 and 3 , we get x = 11 y = 9 product = 11 * 9 = 99 answer b"
Answer: B