Answer:
The total volume of the water in the tank after 20 minutes = 1220 gallons
Step-by-step explanation:
Rate of water pumped into the tank r (t) = 30 (1 - )
Initial volume of water in the tank = 800 gallons
The water in the tank after 20 minutes = Initial volume of water in the tank + Volume of water being pumped in the tank
=
Where a = 0 , b = 20
Put the value of r (t) in above equation we get
=
=
=
= 420 gallon
Now, total volume in the tank
Therefore the total volume of the water in the tank after 20 minutes = 1220 gallons