If the rate of flow in an automatic watering system is 7.49 gallons/hour, how many milliliters per minute (ml/min) is this?
1 gallon = 3.786 liters
1 liter = 1000 mL
just work with the units
7.49 gal/hr * 1hr/60min * 3785mL/gal = (7.49*3785)/60 mL/min