x^2 + bx + 72 = 0 has two distinct integer roots; how many values are possible for b? Options:
A) 3  B) 6  C) 8  D) 12  E) 24
As 72 is positive either both roots are + or -   but as 'b' is +ve, both the roots carry same sign, i.e. +ve, and the factors are as below   72, 1   2, 36   4, 18   8, 9   24, 3   6, 12   ANSWER:12
<result>D</result>
x^2 + bx + 72 = 0 has two distinct integer roots; how many values are possible for b?