Question

A swimming pool is 20 m long 15 m wide and 3 m deep. Find the cost of repairing the floor and wall at the rate of Rs 25 per square metre.

Answer 1

\[\text { Length of the swimming pool = 20 m }\]

\[\text { Breadth = 15 m}\]

\[\text { Height = 3 m }\]

\[\text { Now, surface area of the floor and all four walls of the pool = (length } \times \text { breadth) } + 2 \times \text { (breadth } \times \text { height + length } \times\text {  height) }\]

\[ = (20 \times 15) + 2 \times (15 \times 3 + 20 \times 3)\]

\[ = 300 + 2 \times (45 + 60)\]

\[ = 300 + 210\]

\[ = 510 m^2 \]

\[\text { The cost of repairing the floor and the walls is Rs } 25 m^2 . \]

\[ \therefore\text {  The total cost of repairing 510 m^2 area = 510} \times 25 = \text { Rs } 12750\]