Kimmy is at the beach and wants to rent a jet ski for the day. The cost of the rental is a base charge of $125 and an additional fee of $75 per hour that she keeps the jet ski.

Part A: Write a function that can model this situation where y is the total charge for the rental and x represents the number of hours of the rental.

Part B: Determine how much Kimmy can plan to spend if she rents the jet ski for 5 hours.