Problem 4. Consider the timetable of a service route in the table below. The terminal of this service route is at station A. The transit company has in total 5 vehicles to operate this line. The pull-in and pull-out times are 15 mins each. Given that the transit company would like to minimize the layover time between trips. a. Provide the complete mathematical model formulation. b. Use the mathematical model to get the optimal vehicle schedule. Problem 4. Consider the timetable of a service route in the table below. The terminal of this service route is at station A. The transit company has in total 5 vehicles to operate this line. The pull-in and pull-out times are 15 mins each. Given that the transit company would like to minimize the layover time between trips. a. Provide the complete mathematical model formulation. b. Use the mathematical model to get the optimal vehicle schedule