A rectangular tank is 225 m by 162 m at the base. With what speed must water flow into it through and aperture 60 cm by 45 cm that the level may be raised 20 cm in 5 hour
Here is the link given below for the answer similar to your query :
https://www.meritnation.com/ask-answer/question/wide-at-what-speed-per-hour-must-water-flow-into-it-th/surface-areas-and-volumes/1627873
https://www.meritnation.com/ask-answer/question/wide-at-what-speed-per-hour-must-water-flow-into-it-th/surface-areas-and-volumes/1627873