Each edge of a cube is increased by 50%. Find the percentage increase in the surface area of the cube.

Options

A. 0.5
B. 0.75
C. 1
D. 1.25

Answer

D

Explanation

Let original edge be a Original surface area `=6a^2`
New edge `=150% " of " a=(150a)/(100)=(3a)/(2)`
New suface area `=6 xx ((3a)/(2))^2=(27a^2)/(2)`
Increase in area `=((27a^2)/(2)-6a^2)=(15a^2)/(2)`
Increase % `((15a^2)/(2)xx 1/(6a^2)xx 100)=125 %`