To determine how far the truck driver can travel on 35 gallons of gas, we first need to find the distance traveled per gallon.
From the problem, the truck driver can travel 560 miles on 28 gallons of gas:
\[ \text{Distance per gallon} = \frac{560 \text{ miles}}{28 \text{ gallons}} = 20 \text{ miles per gallon} \]
Now, we can calculate the distance the driver can travel on 35 gallons of gas:
\[ \text{Distance on 35 gallons} = 35 \text{ gallons} \times 20 \text{ miles per gallon} = 700 \text{ miles} \]
So, the truck driver can travel 700 miles on 35 gallons of gas.