If the sum and difference of two numbers are 10 and 8 respectively, then the difference of their square is:
Choose the correct choice from the following answers:  A) 12  B) 28  C) 160  D) 180  E) 80

Rationale: "let the numbers be x and y . then , x + y = 10 and x - y = 8 x 2 - y 2 = ( x + y ) ( x - y ) = 10 * 8 = 80 . answer : e"
Answer: E