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 the 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 is equal to the diameter of the ball.
Therefore, $h=2r$
Ratio of their areas=$\frac{4\pi r^2}{2\pi r(r+h)}=\frac{2r}{r+h}=\frac{2r}{r+2r}=\frac{2}{3}$