Question

Two cubes each of volume 27 cm3 are joined end to end to form a solid. Find the surface area of the resulting cuboid.

Answer 1

Answer:

Let the length of the side of cube be ‘a’ cm.

Volume of each cube = 27 cm3

Volume of cube = a3

∴ a3 = 27 cm3

⇒ a = (27 cm3)1/3

⇒ a = 3 cm

Length of a side of cube = 3 cm

Since, two cubes are joined and a cuboid is formed so,

Length of cuboid = l = 2a = 2 × 3 cm = 6 cm

Breadth of cuboid = b = a = 3 cm

Height of cuboid = h = a = 3 cm

Surface area of cuboid = 2 × (l × b + b × h + l × h)

∴ Surface area of resulting cuboid = 2 × (6 × 3 + 3 × 3 + 6 × 3) cm2

= 2 × (18 + 9 + 18) cm2

= 2 × 45 cm2

= 90 cm2

So, surface area of resulting cuboid is 90 cm2