Question

The curved surface are of a cylinder is 1760 cm² and its base radius is 14 cm. The height of the cylinder is
(a) 10 cm
(b) 15 cm
(c) 20 cm
(d) 40 cm

Answer 1

(c) 20 cm
Curved surface area of the cylinder$=2\mathrm{\pi }rh$
$=2\times \frac{22}{7}\times 14\times h$
Therefore,
$$\begin{gathered} 2\times \frac{22}{7}\times 14\times h=1760 \\ \Rightarrow h=\frac{1760}{88}\text{cm} \\ \Rightarrow h=20\text{cm} \end{gathered}$$
Hence, the height of the cylinder is 20 cm.