Question

A plate of metal 1cm thick, 9cm broad and 81cm is melted into a cube. find the difference in the surface area of the two solid.

Answer 1

volume of cuboid=volume of cube

1*9*81=a*a*a

9*9*9=a^3

9^3=a^3

9=a

surface area of cuboid = 2(lb+ bh+lh)

=2(9+81+729)

=2(819)

=1638 cm^2

surface area of cube= 6a^2

=6*9*9

=486cm^2

difference= 1638-486

=1152 cm^2