Answer:
17hrs (a little more)
Explanation:
The tank is 1500 gallon capacity, it already contains 200 gallons.
1500-200=1300
Now, you have to figure how many hrs it will take at 75 gallons / hr to reach the additional 1300 gallons.
1300รท75= 17.33
It says full, but not overflowing. So I would say around 17hrs