Question

In a temple, there are $25$ cylindrical pillars. the radius of each pillar is $28cm$ and height $4m$. Find the total cost of painting the curved surface area of pillars at the rate of Rs. $8$ per $m^2$

Answer 1

We have,

$r=$ radius of cylindrical pillar $=28cm=\frac{28}{100}m$

$h=$ height of cylindrical pillar $=4m$

$\therefore$ curved surface area of a cylindrical pillar = $2\pi rh=2\times \frac{22}{7}\times \frac{28}{100}\times 4c{m}^2$

$\therefore$ Curved surface area of $25$ pillar = $2\times \frac{22}{7}\times \frac{28}{100}\times 4\times 25m^2=176m^2$

Hence, total cost of painting at the rate of Rs $8$ per $m^2=Rs(176\times 8)=Rs1408$