Once cleaned by the car washing machine, a team of workers completes the process as follows:

Exterior workers wipe down the exterior of the car to prevent water spots from forming, spray the tires with tire solvent, and then carefully scrub off any bugs that weren't removed by the washing machine. This takes each worker $18$ minutes and there are $4$ exterior workers.

Interior workers dust all surfaces with damp cloths and clean all interior windows. This takes each worker $20$ minutes and there are $6$ interior workers.

Trojan Car Wash is a successful business, earning $$18$ profit per car washed, with $14$ customers arriving per hour on a typical day. You can assume steady state for all calculations $($no cold start$)$ and all answers are average numbers $($so do not truncate$).$ The car wash is open $10$ hours per day, $360$ days per year.

a$.(6$ points$)$ What is the capacity of Trojan Car Wash per hour? Be sure to show work and justify your answer.