What will be the percentage increase in the area of the cube's surface if each of the cube's edges grows by 30%? Select the correct option:
A) 70%  B) 69%  C) 80%  D) 82%  E) 55%
The question is very easy. My logic is the following:   A surface = 6*a^2   After 30% increase A surface = 6* ((1.3a)^2) = 6*1.69*a^2   The increase in the surface area = (6*1.69*a^2 - 6*a^2)/6*a^2 = (6*a^2(1.69-1))/(6*a^2) = 1.69-1= 
<gadget id="calculator">1.69-1</gadget>
<output>0.69</output>
0.69= 69%   Answer : 69%
<result>B</result>
What will be the percentage increase in the area of the cube's surface if each of the cube's edges grows by 30%?