Question:
The curved surface area of a cylinder is 1210 cm2 and its diameter is 20 cm. Find its height and volume.
Solution:
Curved surface area = 1210 cm2
Suppose that the height of cylinder is h cm.
We have r = 10 cm
Now, $1210=2 \pi r h$
$\Rightarrow 1210=2 \times \frac{22}{7} \times 10 \times h$
$\Rightarrow h=\frac{1210 \times 7}{2 \times 22 \times 10}=\frac{11 \times 7}{2 \times 2}=19.25 \mathrm{~cm}$
$\therefore$ Volume of the cylinder $=\pi r^{2} h$
$=\frac{22}{7} \times 10^{2} \times 19.25 \mathrm{~cm}^{3}$
$=2200 \times 2.75 \mathrm{~cm}^{3}=6050 \mathrm{~cm}^{3}$