Question

A cuboid of sides 5 cm, 10 cm and 20 cm are melted to form a new cube. What is the ratio between the total surface area of the cuboid and that of the cube?

Answer 1

Volume of cuboid=5×10×20= 1000

Volume of cube=volume of cuboid=1000

So, a^3=1000

a=10(here 'a' is the side of cube)

Surface area of cuboid=S1=2(lb+lh+hb)

S1=700

Surface area of cube=S2=6a^2

S2=600

Therefore,

S1:S2= 7:6