Question

The lateral surface area of a cube is 900 sq.cm. Find the length of rope require to cover all it's edges.
1. 180 cm
2. 160 cm
3. 150 cm
4. 110 cm

Answer 1

Correct Answer - Option 1 : 180 cm

Given

Lateral surface area = 900 sq.cm

Formula used 

Lateral surface area = 4(side)²

Sum of all edges = 12 × side [As there are 12 edges of a cube]

Calculation

Lateral surface area = 900

4(side)² = 900

⇒ (Side)² = 225

⇒ (Side) = 15

Total rope required to cover all edges = 15 × 12

⇒ 180 cm

∴ Total length of rope required is 180 cm