Question

The diameter and height of a cylindrical chimney are $2m$ and $14m$ respectively. Find the cost of painting its exterior curved surface at the rate of Rs. $150$ per $m^2$.

Answer 1

Given, $d=2m$ and $h=14m$.

Cost of painting $=$Rs. $150/m^2$

$\therefore$ exterior curved surface area of chimney$=\left(2\pi r\right)h=\left(\pi d\right)h=\frac{22}{7}$ $\times 2\times 14=88m^2$

$\therefore$cost of painting $=$ Rs.$88\times 150=$ Rs.$13,200$