If the sum of two numbers is 30 and the sum of their squares is 840, then the product of the numbers is
Answers.
A) 40
B) 44
C) 80
D) 88
E) 30

Rationale: sol . let the numbers be x and y . then , ( x + y ) = 30 and x 2 + y 2 = 840 . now , 2 xy = ( x + y ) 2 - ( x 2 + y 2 ) = ( 30 ) 2 - 840 = 900 - 840 = 60 xy = 30 . answer e
Answer: E