### Queueing Problem : Labor Usage, Percentage Unused Avaliable Labor, Exponential Distribution

A certain service station uses a team of 3 mechanics in one repair station to work on each car that needs repair. This team can repair cars at a rate of 9 per day. Cars arrive for repairs at the station at the rate of 4.5 per day. The service station owner has decided that this team is not very efficient in terms of labor usa