Question

Two identical cubes each of volume 64 cm³ are joined together end to end. What is the surface area of the resulting cuboid?

Answer 1

Let the side of one cube = a

Surfaces area of resulting cuboid = 2(Total surface area of a cube) – 2(area of single surface)

We know that,

Total surface area of cube = 6a² , where a = side of cube

⇒ Surfaces area of resulting cuboid = 2(6a²) – 2(a²) = 10a²

Also,

According to the question,

Volume of cube = 64 cm³

Volume of cube = a³

64 = a³

a = 4 cm

Therefore,

Surface area of resulting cuboid = 10a² = 10(4)² = 160 cm²