Final answer:
Raoul will have to pay for an hour, which is divided into four 15-minute periods at $3 each, totaling $12.
Step-by-step explanation:
Raoul needs to use the Pineville Library computers for his school project. He is allowed 30 minutes for free, and since he needs the computer for an hour and a half, he will have to pay for an additional hour.
The library charges $3 for every 15 minutes after the initial 30 minutes.
To calculate the fee, we divide the additional hour into 15-minute periods.
Number of 15-minute periods in an hour: 60 minutes / 15 minutes = 4 periods.
Cost for each period: $3.
Total fee = 4 periods x $3/period = $12.
Therefore, Raoul can expect to pay a fee of $12 for using the computer for an hour and a half.