Volume of water that enters the tank is 20m^3/h. Level of water inside the tank is 50% wich is equal to 400m^3. Pump is able to deliver 30m^3/h . how long will it take to empty the tank ?

The net rate of draining is 30-20 = 10 m^3/hr

assuming that there are in fact 400m^3 of water in the tank, it will drain in
400/10 = 40 hr

although, it is unclear whether there is only 50% of 300 m^3 in the tank. Adjust the result as needed.

To find out how long it will take to empty the tank, we first need to calculate the volume of water that needs to be emptied from the tank.

The level of water inside the tank is given as 50%, which is equal to 400m^3. This means that half of the tank is filled with water, so the total volume of the tank is 2 * 400m^3 = 800m^3.

The pump is able to deliver 30m^3/h, which means it can remove 30m^3 of water from the tank in 1 hour.

To calculate the time it will take to empty the tank, we divide the total volume of the tank by the pump's flow rate:

Time = Volume / Flow rate

Time = 800m^3 / 30m^3/h

Now we can calculate:

Time = 800m^3 / 30m^3/h = 26.67 hours

Therefore, it will take approximately 26.67 hours to empty the tank.