The registration desk at your local hospital receives 7 patients per hour in average and the number of arrivals follows a Poisson distribution while service time, which follows an exponential distribution, is 5 minutes in average. Assuming that the desk is open 10 hours per day, that there is no limit on the number of patients on line, and that the queuing discipline is first come first served (FCFS):

1. What is the average waiting time?
2. What is the average number of patients in this service area?
3. What is the average time to spend in the service area?
4. If we put three seats in this service area (one for the person receiving the service and two seats for those who are waiting for service), what is the probability that all these seats be empty? and
5. what is the probability that all seats be occupied?
6. What should we do to bring the average time in the service area to 10 minutes?