What will be the percentage increase in the area of the cube's surface if each of the cube's edges grows by 50%?  Choose the most appropriate option:
A) 125 %
B) 150 %
C) 100 %
D) 90 %
E) 85 %

Rationale: "the question is very easy . my logic is the following : a surface = 6 * a ^ 2 after 50 % increase a surface = 6 * ( ( 1.5 a ) ^ 2 ) = 6 * 2.25 * a ^ 2 the increase in the surface area = ( 6 * 2.25 * a ^ 2 - 6 * a ^ 2 ) / 6 * a ^ 2 = ( 6 * a ^ 2 ( 2.25 - 1 ) ) / ( 6 * a ^ 2 ) = 2.25 - 1 = 1.25 = 125 % answer : a"
Answer: A