Question

The radii of two circular ends of a frustum of a cone shaped dust bin are $15cm$ and $8cm$. If its depth is $63cm$, find the volume of the dust bin.

Answer 1

Solution:

Let $r_1=15cm,r_2=8cm$ and $h=63cm$

Volume of the dustbin (frustrum)$=\frac{1}{3}\times \pi \times h\times (r_1^2+r_2^2+r_1{r}_2)$

$=\frac{1}{3}\times \frac{22}{7}\times 63\times ({15}^2+8^2+15\times 8)$

$=66(225+64+120)c{m}^3$

$=66\times 409c{m}^3$

$=26994c{m}^3$