Question

if each edge of a cube is increased by 25% then find the percentage increase in its surface area

Answer 1

Edge of a cube=a
Surface area of this cube =6a^2

New edge of cube =a+4*1/4=a+a/4=5a/4
New surface are of this cube =6*5a/4*5a/4
=6*25a^2/16=75a^2/8
Increase in surface area =75a^2/8-6a^2=(75a^2-48a^2)/8=27a^2/8
Percent increase =27/8*100=337.5%