A rectangular reservoir measures 80 meters by 60 meters at its base and contains water to a depth of 6.5 meters. If water flows out through a pipe with a square cross-section of 20 cm on each side at a speed of 15 km/h, how long will it take to empty the reservoir?

Explanation

To find the time required to drain the reservoir, calculate the volume of water (base area × depth), convert the pipe's cross-sectional area to square meters, and determine the flow rate in cubic meters per hour. Dividing the total volume by the flow rate gives the time needed, which is 52 hours.