Question

A cricket ball of radius $r$ is exactly fitted in a cylindrical tin as shown in the figure below. The ratio of surface areas of cricket ball to the surface area of tin is

• A. 1:3
• B. 2:3
• C. 3:1
• D. 3:2

Answer 1

The correct option is B

2:3

The height of cylinder will be equal to the diameter of the ball.
Therefore, $h=2r$
Ratio of their areas $=\frac{4\pi r^2}{2\pi r(r+h)}$

$=\frac{2r}{r+h}=\frac{2r}{r+2r}$

$=\frac{2}{3}$