Final answer:
The tank with an initial volume of 450 gallons, draining at 20 gallons per minute, will have 310 gallons remaining after 7 minutes.
Step-by-step explanation:
The student asks how many gallons will be in a 450 gallon tank after it has been draining at a rate of 20 gallons per minute over a period of 7 minutes.
To solve this, we start with the initial amount of water in the tank, which is 450 gallons.
We then calculate the total amount of water that has drained from the tank after 7 minutes by multiplying the drain rate (20 gallons per minute) by the time (7 minutes).
Total gallons drained after 7 minutes = 20 gallons/minute × 7 minutes = 140 gallons.
Next, we subtract the total gallons drained from the initial volume of the tank to find out how much water remains:
Gallons remaining after 7 minutes = Initial volume - Total gallons drained = 450 gallons - 140 gallons = 310 gallons.
Therefore, after 7 minutes, there will be 310 gallons of water remaining in the tank.