Question

. A swimming pool is 20 m in length, 15 m in breadth and 4 m in depth.Find the
cost of cementing its floor and walls at the rate of Rs.12 per square metre.

Answer 1

Answer:

Given that,

Length of the swimming pool is, l = 20 m

Breadth of the swimming pool is, b = 15 m

Height of the swimming pool, h = 4 m

To find,

The cost of cementing its floor and walls at the rate of Rs.12 per square metre.

Solution,

The surface area of cuboid to be cemented is given by :

The surface area of the cuboid = area of 4 walls + area of floor

The surface area of the cuboid = Lateral surface area of cuboid + area of floor

The surface area of the cuboid is

2h(l+b)+lb

=2×4×(20+15)+20×15

=580 m

2

For Rs.12 per square metre,

\begin{gathered}A=\text{Rs} 580\times 12\\\\A=\text{Rs}\ 6960\end{gathered}

A=Rs580×12

A=Rs 6960

Answer 2

Given:

✰ Length of the swimming pool ( l ) = 20 m

✰ Breadth of the swimming pool ( b ) = 15 m

✰ Depth of the swimming pool ( d ) = 4 m

To find:

✠ The cost of cementing its floor and walls at the rate of Rs. 12 per square metre.

Solution:

Let's understand the concept! First we will find the area of four walls of the swimming pool and then the area of floor of the swimming pool both by using formula. Putting the values in the formula and then doing the required calculations. After finding them, we will add both of them to get the area of the floor. Then, we will find the cost of cementing its floor and walls.

Let's find out...✧

✭ Area of 4 walls of the room = 2( l + b ) × d ✭

Putting the values in the formula, we have:

➛ Area of 4 walls of the room = 2( 20 + 15 ) × 4

➛ Area of 4 walls of the room = 2 × 35 × 4

➛ Area of 4 walls of the room = 70 × 4

➛ Area of 4 walls of the room = 280 m²

✭ Area of floor = l × b ✭

➛ Area of floor = 20 × 15

➛ Area of floor = 300 m²

Now,

➛ The total area of the swimming pool = Area of 4 walls of the room + Area of floor

➛ The total area of the swimming pool = 280 + 300

➛ The total area of the swimming pool = 580 m²

then,

➤ The cost of cementing its floor and walls per m² = Rs. 12

➤ The cost of cementing its floor and walls per 580 m² = Rs. 12 × 580

➤ The cost of cementing its floor and walls per 580 m² = Rs. 6960

∴ The cost of cementing its floor and walls of the swimming pool = Rs. 6960

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