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

Let 'a' be the side of one cube.

As two cubes are joined together, the surfaces that are joined together will not be included in the surface area of resulting cuboid.

So,

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

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

[As total surface area of cube = 6a² , where a = side of cube]

Also,

Volume of cube = a³

64 = a³

[Given volume of cube is 64 cm³ ]

a = 4 cm

Therefore,

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