Water in a rectangular reservoir having base 80m by 60m is 6.5m deep. In what time can the water be emptied by a pipe of which the cross-section is a square of side 20cm, f the water runs through the pipe at the rate of 15km/hr.

Explanation

Given that
Flow of water =`15 (km)/(hr)`
`15000 m/(hr)`
Volume of water coming out of the pipe in one hour
`20/100xx20/100xxpm5000=600m^3`
Volume of the tank=`80xx60xx6.5`
`=311200m^3`
Time taken to emptythe tank =(volume of tank) / (volume of water coming out of the pipe inone hours)
`=31200/600`
`=52 hours`