Respuesta :

It’s 10.5 I’m pretty sure
Calculate the difference of gallons over each of the 3 hours. (Gallons at 6 hours- Gallons at 3 hours). In this example it is 10.5 Gallons per 3 hours. 10.5Gallons/3hours is 3.5 Gallons per hour. Let me know if you need further explanation.