Question

Find the volume of the frustum cone whose base and top radius is $12$ m and $4$m respectively. The height of the cone is $21$ m. (Use $\pi =\frac{22}{7}$).

• A. $4,476$ $m^3$
• B. $4,576$ $m^3$
• C. $4,376$$m^3$
• D. $4,276$$m^3$

Answer 1

The correct option is B $4,576$ $m^3$

Volume of frustum $=$ $\frac{1}{3}\pi (R^2+r^2+Rr)\times h$

$=$ $\frac{1}{3}\times \frac{22}{7}({12}^2+4^2+12\times 4)\times 21$

$=22(144+16+48)=4576$ $m^3$