Water flows at the rate of 5 kg per hour through a pipe of diameter 14 cm into a rectangular tank which is 25 m long and 22 m wide. Find the time in which the level of water in the tank rises by 21 cm. [Take = 22/7]

2.31 hours

flow rate = 5kg/h = 5000g/h

density of water = $\rho =1g/cm^3$

flow rate = $5000cm^3/h$

volume filled = 25×22×21

so let x hours be required

so $5000cm^3×x=25×22×21$

so $x = 2.31h$