A swimming pool is of dimensions 25 m × 12 m × 5.5 m. What is the cost of cementing its floor and wall at the rate of Rs 12.50 per square metre?

To find the cost of cementing the floor and wall of the swimming pool, we need to calculate the total surface area of both the floor and the walls separately.

1. Calculate the surface area of the floor: The floor of the swimming pool is a rectangle, so we can use the formula for the area of a rectangle, which is length × width. Given that the length of the pool is 25 m and the width is 12 m, we can calculate the area of the floor as follows: Area of the floor = 25 m × 12 m = 300 square meters.

2. Calculate the surface area of the walls: The walls of the swimming pool form a rectangular prism, so we need to calculate the area of each side and then add them together. The formula for the area of a rectangle is length × height, and since the pool has four walls, we need to calculate the area of each wall separately. Given that the length of the pool is 25 m, the height is 5.5 m, and the width is 12 m, we can calculate the area of each wall as follows: Area of each wall = length × height = 25 m × 5.5 m = 137.5 square meters. Since there are four walls, the total area of the walls is: Total area of the walls = 4 × 137.5 square meters = 550 square meters.

3. Calculate the total surface area: To find the total surface area, we need to add the area of the floor and the area of the walls together: Total surface area = Area of the floor + Total area of the walls Total surface area = 300 square meters + 550 square meters = 850 square meters.

4. Calculate the cost of cementing: Given that the rate of cementing is Rs 12.50 per square meter, we can calculate the cost of cementing the pool by multiplying the total surface area by the rate: Cost of cementing = Total surface area × Rate Cost of cementing = 850 square meters × Rs 12.50 per square meter = Rs 10,625.

Therefore, the cost of cementing the floor and wall of the swimming pool at the rate of Rs 12.50 per square meter is Rs 10,625.