A large hair salon needs to make an agreement with a laundry service for washing and cleaning their hairdresser aprons. The salon accumulates 800 dirty aprons per day. When the laundry service comes to collect the dirty aprons, they charge a fixed fee of 81 TL per service and a variable cost of 0.6 TL per apron. The cost of keeping a dirty apron for one day is 0.03 TL/apron, while the cost of keeping a clean apron for one day is 0.015 TL/apron.

a) What should be the policy regarding the frequency of having the aprons cleaned?

b) What would be the total cost for each cleaning cycle?