Answer:
It will take 720 minute to fill the tank
Step-by-step explanation:
We have given that length of rectangular tank l = 12 m
Width w = 8 m
Rate at which water is filled in the tank = 550 l/min
And rate at which water come out from the tank = 150 l/min
So net rate of filling the tank = 550-150 = 400 l/min
Height up to which we have to fill the tank h = 3 meter
So volume of the tank

We know that

So

So required time to fill the tank
