Parking in a student lot costs $1 for the first half hour and $1.50 for each hour thereafter. A partial hour is charged the same as a full hour. What is the longest time that a student can park in this lot for $7?

4.5 hours

Step-by-step explanation:

First subtract $7 -$1 for the first half hour to see how much money is left over

$7-$1= $6 dollars left

$1.50 for each hour

6/1.50= 4 hours

Don't forget the first half hour.  So 4.5 hours