Solution: Suppose in hours water will be 3 metres deep in the tank .
Volume of water in the tank
Area of the cross - section of the pipe
Volume of water that flows in the tank in hours
(Area of cross section of the pipe )
(speed of water )
(time)
[
speed = 15km/hr=15000m/hr ]
.
since the volume of water in the tank is equal to the volume of water that flows in the tank in hours .
450
hours .