algebra
posted by christina .
parking in a student lot cost $1 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 lot for $9 what is the answer

Parking in a student lot costs$1 for the first half hour and $1.75 for each hour thereafter. A partial hour is charged the same as full hour. What is the longest time that a student can park in this lot for $8?