Answer: 1.7
Explanation:
The rate of gallons per hour is the same as the unit rate. You want to find out how many gallons are filled in one hour, so divide 3 down to one, 3 divided by 3 is one. Then, also divide 5 by 3. 5 divided by 3 is 1.6666... and as an hour is out of 60, round it to 1.7.
I hope this helps!