We have an initial value of $43 and every hour the price of the reservation increases $8.70, then, the function that determinates the price for the meeting room is

The history club have a limit value that is $77.80, then, to find the amount of hours they can spend at the meeting room we just need to solve the following inequality:

Solving for t:

The maximum amount of hours they can spend in the meeting room is 4 hours.