Question

Two cubes, each of volume 512 cm³ are joined end to end. Find the surface area of the resulting cuboid.

Answer 1

Given,

Volume of each cube = 512 cm³

Let length of edge of each cube = a cm

So,

= a³ = 512

= a = \(\sqrt[3]{512}\) = 8 cm

When these two cubes are joined end to end a cuboid is formed:

Length of cuboid = 8 + 8 = 16 cm

Breadth = 8 cm

Height = 8 cm

Surface area of resulting cuboid = 2(lb x bh x lh) = 2(16 x 8 + 8 x 8 + 8 x 16)

= 2(128 + 64 + 128) = 2 x 320 = 640 cm²