What is the cost to rent a trailer for 8.4 hours? Can someone please explain how to solve this problem.

The charge to rent a trailer is $15 for up to 2 hours plus $9 per additional hour or portion of an hour. Find the cost to rent a trailer for 2.7 hours, 3 hours, and 8.4 hours. Then graph all ordered pairs, (hours, cost), for the function. a. What is the cost to rent a trailer for 2.7 hours? $ 24 b. What is the cost to rent a trailer for 3 hours? $ 24 c. What is the cost to rent a trailer for 8.4 hours? X