One root of the quadratic equation x2 – 12x + a = 0, is thrice the other. Find the value of a?

A. 29
B. 27
C. 28
D. 7
Explanation:
Let the roots of the quadratic equation be x and 3x.
Sum of roots = -(-12) = 12
a + 3a = 4a = 12 => a = 3
Product of the roots = 3a2 = 3(3)2 = 27.