If the sum of two numbers is 18 and the sum of their squares is 220, then the product of the numbers is Pick one:
A) 40  B) 44  C) 52  D) 88  E) 90

Rationale: "sol . let the numbers be x and y . then , ( x + y ) = 18 and x 2 + y 2 = 220 . now , 2 xy = ( x + y ) 2 - ( x 2 + y 2 ) = ( 18 ) 2 - 220 = 324 - 220 = 104 xy = 52 . answer c"
Answer: C