woodlawn is a taxi company and serves the car wash for the registered taxi drivers. the drivers arrive at the washing space to get their car washed according to the poisson process, with an average arrival rate of 8 cars per hour. currently, the washing process is low-tech and is done manually by the workers. there are two spots (one worker per spot) for washing the car. service times for washing each car are random, with a mean of 12 mins and a standard deviation of 6 mins.