Two numbers differ by 5. If their product is 336, then the sum of the two numbers is	Choose one
A) 21 B) 28 C) 37 D) 51 E) None of these
Sol.   Let the number be x and y.   Then, x - y = 5 and xy = 336.   ⇔ (x+y)2 = (x-y)2 + 4xy = 25 + 4 x 336 = 1369   ⇒ x+y = √1369 = 37.   Answer 37
<result>C</result>
Two numbers differ by 5. If their product is 336, then the sum of the two numbers is