Question

A swimming pool is $20m$ in length, $15m$ in breadth and $4m$ in-depth. Find the cost of painting of its four walls at the rate of $Rs20$ per square metre.

Answer 1

Step 1: Finding the area of four walls

Given,

Length $\left(l\right)=20m$

Breadth $\left(b\right)=15m$

Height $\left(h\right)=4m$.

Area of four walls $=2(l+b)xh$

$$\begin{gathered} =2(20+15)x4 \\ =2x35x4 \\ =280m^2 \end{gathered}$$

Step 2: Finding the cost of painting four walls.

Since, cost of painting is at the rate of $Rs20$ per square metre.

Therefore, total cost of painting its four walls $=20\times 280$

$=Rs560$

Hence, the cost of painting its four walls at the rate of $Rs20$ per square metre is $Rs560$.