Question

A rectangular paper of width 42 cm is rolled along its length and a cylinder of radius 20 cm is formed. Find the volume of the cylinder.

• A. 25 Litres
• B. 50 Litres
• C. 52.8 Litres
• D. 60 Litres

Answer 1

The correct option is C

52.8 Litres

When a rectangle is rolled along its length, the width of the rectangle will be the height of a cylinder.
Hence, height of the cylinder, h = 42 cm
Given, radius, r = 20 cm
Hence, volume of the cylinder,
$V=\pi r^{2}h=\frac{22}{7}\times 20\times 20\times 42=52800{\text{cm}}^3$

We know, 1 L = 1000 $c{m}^3$
Hence, the volume of the cylinder = $\frac{52800}{1000}$ = 52.8 Litres