If the product of two numbers is 10 and the sum of the two numbers is 7, then the larger of the two numbers is ----
A
-2
B
2
C
4
D
5
Correct Answer: 5
Let the number be a, b So, a + b = 7 b = ( 7 - a) and, ab = 10 a( 7 - a) = 10 a2 - 7a + 10 = 0 (a - 5) ( a + 2) = 0 a = 5, 2 So, the larger of the two number is 5