What will be the percentage increase in the area of the cube's surface if each of the cube's edges grows by 10%? Choose the correct choice from the following options:
A) 25%  B) 28%  C) 21%  D) 30%  E) 32%
The question is very easy. My logic is the following:   A surface = 6*a^2   After 10% increase A surface = 6* ((1.1a)^2) = 6*1.21*a^2   The increase in the surface area = (6*1.21*a^2 - 6*a^2)/6*a^2 = (6*a^2(1.21-1))/(6*a^2) = 1.21-1= 
<gadget id="calculator">1.21-1</gadget>
<output>0.21</output>
0.21= 21%   Answer : 21%
<result>C</result>
What will be the percentage increase in the area of the cube's surface if each of the cube's edges grows by 10%?