# An wooden toy is made by scooping out a hemisphere of same

Question:

An wooden toy is made by scooping out a hemisphere of same radius from each end of a solid cylinder. If the height of the cylinder is 10 cm, and its base is of radius 3.5 cm, find the volume of wood in the toy. (Use π = 22/7).

Solution:

Volume of wood in the toy = Volume of cylinder − 2(Volume of hemisphere)

$=\pi r^{2} h-2 \times \frac{2}{3} \pi r^{3}$

$=\frac{22}{7} \times(3.5)^{2} \times 10-2 \times \frac{2}{3} \times \frac{22}{7} \times(3.5)^{3}$

$=385-179.67$

$=205.33 \mathrm{~cm}^{3}$