If the sum of two numbers is 30 and the sum of their squares is 840, then the product of the numbers is	Options.
A) 40
B) 44
C) 80
D) 88
E) 30
Sol.   Let the numbers be x and y.   Then, (x+y) = 30 and x2 + y2 = 840.   Now, 2xy = (x+y)2 - (x2 + y2)   = (30)2 - 840= 900 - 840= 
<gadget id="calculator">900 - 840</gadget>
<output>60</output>
60   xy= 30.   Answer 30
<result>E</result>
If the sum of two numbers is 30 and the sum of their squares is 840, then the product of the numbers is