If each edge of a cube is doubled, then the percentage increase in its total surface area is

A. 200%

B. 300%

C. 150%

D. 600%

Correct Answer is :

B. 300%

Explanation

If each edge of a cube is doubled, then the percentage increase in its total surface area is 300%. Surface area of a cube = 6 ×(side)2 Let the side of cube = 'a' then its surface area = 6a2 new side of a cube = 2a then its surface area = 6(2a)2=24a2 Therefore, Percentage increase = [(24a2−6a2)/ 6a2] ×100 =300%