Question

The volume of a cylinder is $231c{m}^3$ and its height is 6 $cm$. A ball will fit inside the cylinder if its radius is ______.

• A. 3 $cm$
• B. 4 $cm$
• C. 2.5 $cm$
• D. 5 $cm$

Answer 1

Answer: (A), (C)

The correct options are
A

3 $cm$

C

2.5 $cm$

Volume of cylinder $=\pi \times r^2\times h$
$\Rightarrow 231=\frac{22}{7}\times r^2\times 6$
$\Rightarrow r^2=231\times \frac{7}{22}\times \frac{1}{6}$
$\Rightarrow r^2=12.25$
$\Rightarrow r=3.5$
So, a ball will fit inside the cylinder if its radius is less than or equal to 3.5 $cm$.