The percentage increase in the surface area of a cube when each side is doubled is :
A
200%
B
300%
C
150%
D
50%
Correct Answer: 300%
We know that⇒ Total surface area of a cube
⇒ 6a2
⇒ If each side is doubled i.e. 2a
⇒ Total surface area of a cube
⇒ 6 × (2a)2
⇒ 24a2
Increase in surface area = 24a2 - 6a2 = 18a2
∴ % Surface area of cube will increase :
$$\frac{{18{a^2}}}{{6{a^2}}} \times 100 $$
= 300%
