Question

A rectangular swimming pool with a flat bottom is 20 feet by 12 feet. How long will it take to fill the swimming pool to 5 feet if water is being pumped into the pool at 30 cubic feet per minute?

Answer 1

The given dimensions of the rectangular swimming pool are =

Length = 20 feet

Width = 12 feet

Height upto which the water should be filled up = 5 feet

So, the total volume of water needed to fill the pool will be =

$20\times12\times5=1200$ cubic feet

The water is pumped at a speed of = 30 cubic feet per minute.

So, to fill 1200 cubic feet, the time taken will be = $\frac{1200}{30} =40$

Hence, it will take 40 minutes to fill the pool.

Answer 2

20 feet * 12 feet * 5 feet
= 20 * 12 * 5 feet ^3
= 1200 feet^3

1200 feet^3 / (30 feet^3 / minute)
= (1200 / 30) minutes
= (120 / 3) minutes
= 40 minutes