Question

A building has $8$ right cylindrical pillars whose cross sectional diameter is $1$ m and whose height is $4.2$ m. Find the expenditure to paint these pillars at the rate of Rs.$24$ per $m^2$

• A. Rs.$2534.40$
• B. Rs.$2506.13$
• C. Rs.$2610.9$
• D. Rs.$2514.5$

Answer 1

The correct option is A Rs.$2534.40$

Given, diameter $=1$m, radius $=$ $\frac{diameter}{2}=\frac{1}{2}$
height of cylinder $=4.2$ m
Curved surface area of cylinder $=2\pi rh=2\pi \times \frac{1}{2}\left(4.2\right)=13.2m^2$
$\therefore 8\times$ right circular cylinder $=8\times 13.2=105.6m^2$
$\therefore$ cost of painting pillar at the rate of Rs. $24$ per $m^2=24\times 105.6=$ Rs.$2534.4$