Well, Google says 1 fluid ounce = 0.0078125 gallons.
Make an equation.
17h = amount of liquid leaked.
There are 24 hours in a day.
So 17*24=408
408 fluid ounces.
Convert that into gallons and you get 3.1875 gallons.
The pipe would leak 3.1875 gallons per day.
(Did I get this explanation wrong?)