5 2/3 gallons of fuel ... 2 hour trip
x gallons of fuel = ? ... 1 hour
If you would like to know how many gallons were used each hour, you can calculate this using the following steps:
5 2/3 * 1 = 2 * x
17/3 = 2 * x /2
x = 17/6 = 2 5/6 gallons of fuel
The correct result would be 2 5/6 gallons of fuel.