Question

Parking in a student lot costs $2 for the first half hour and $1.75 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 lost for $7?

Answer 1

The longest time that a student can park in this parking lot for $7 is 2 in a half hours

Answer 2

An easier way to think of this problem is just keep adding for each additional hour: 

0.5 hours --> $2 

1.5 hrs --> $3.75 

2.5 hrs --> $5.50 

3.5 hrs --> $7.25 

and since you can only spend $7, the maximum time is 2.5 hours