Numbers Q10

10.If the sum of two numbers is 22 and the sum of their squares is 404, then the product of the numbers is

            A.  40 B.  44

             C.  80            D.  88

Answer:

Let the numbers be x and y.

Then, (x+y) = 22

and x2+y2  = 404.

Now, 2xy= (x+y)2 - (x2+y2)

= (22)2 - 404

= 484 - 404

= 80

Therefore xy          = 40.