Question

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

Answer 1

Given :-

Length of the Pool = 20m

Breadth of the Pool = 15m

Height of the Pool = 4m

Rate of Cementing = Rs,12 per m

To Find :-

• Cost of Cementing the Pool

Solution :-

➞ Total Area = Area of 4 walls + Area of Floor

➞ Total Area = 2 (l + b) × h + l × b

➞ Total Area = 2 ( 20 + 15 ) × 4 + 20× 15

➞ Total Area = 2 × 35 × 4 + 20 × 15

➞ Total Area = 2 × 35 × 4 + 300

➞ Total Area = 8 × 35 + 300

➞ Total Area = 280 + 300

➞ Total Area = 580m²

________________

⟾ Cost of Cementing 1m² = Rs,12

⟾ Cost of Cementing 580m² = Rs, 12× 580

⟾ Cost of Cementing 580m² = Rs,6960

________________

Therefore, Cost of Cementing the pool is Rs,6960

________________

Answer 2

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

For Rs.12 per square metre,

So, the cost of cementing its floor and walls at the rate of Rs.12 per square metre is Rs 6960.