Q. 2 cubes, each of volume 27 cm³, are joined end to end, then the surface area of the resulting cuboid is:

Correct Answer: (C) 90 cm²

Explanation:

To determine the surface area of the resulting cuboid when two cubes of volume 27 cm³ each are joined end to end, follow these steps:

1. Find the side length of each cube:
Volume of a cube = s³ ⇒ s = ∛27 = 3 cm

2. Determine the dimensions of the cuboid:
– When two cubes are joined end to end along one edge (let’s assume the length), the dimensions of the resulting cuboid are:

Length = 2s = 2 × 3 = 6 cm
Width = s = 3 cm
Height = s = 3 cm

3. Calculate the surface area of the cuboid:
Surface Area = 2(lw + lh + wh)
Substituting the dimensions:
= 2(6 × 3 + 6 × 3 + 3 × 3)
= 2(18 + 18 + 9)
= 2 × 45 = 90 cm²

Answer: (C) 90 cm²