Question

a swimming pool is 20m in length 15 breadth and 4m in depth.find the cost of cementing its floors and walls @ 12 rupees per square metre ​

Answer 1

Answer:

6960

Step-by-step explanation:

Length of pool = 20 m

Width of pool = 15 m

Depth = 4 m

So,

Area of the floor = 15 * 20

                          = 300 m²

There are 2 walls along the length and 2 walls along the width.

So the total area of the walls is

=> {2 * (20 * 4) + 2 * (15 * 4)}

=> (160 + 120)

=> 280 m².

Total area = 300 + 280 = 580 m².

Cost per m² = 12 rupees.

Total cost = 580 * 12 = 6960

Therefore, required cost = 6960

Hope it helps!

Answer 2

Answer:

First of all, cement will be applied only  at the base and the four walls of the pool. So, the area we have to find is 2(lh + bh) + lb

'l' for length

'b' for breadth

'h' for height

=> 2(lh + bh) + lb

=> 2(20 x 4 + 15 x 4) + 20 x 15

=> 2 (80 + 60) + 300

=> 2(140) + 300

=> 280 + 300

=> 580 m^2

Now, cost = 12 x 580

                 =  6960 rupees