Let's start with the known information.
There is a set value, which is $25.50. Next it was given that the rate is $1.50 per mile. Lastly, Jack does not want to spend more than $60 total.
With these information, you can set up an inequality.
Let x be the number of miles.
1.50x + 25.50 ≤ 60
Subtract 25.50 on both sides
1.50x ≤ 34.50
Divide both sides by 1.5
x ≤ 23
This means that the greatest number of miles Jack can drive is 23.