Customers arrive at a carwash according to Poisson Distribution with mean 4 per hour. Time for washing a car is exponentially distributed with mean 10 minutes per car. The facility contains one service bay

1- What percent of the time the facility will be idle?

2- How many cars will be waiting for service when a customer arrives? (expected value)

3- How many cars will be in the facility when a customer arrives?

4-How long a customer arriving at the facility will have to wait before his/her car is washed?

5- How long a customer arriving at the facility will take till his/her car is washed and ready to leave the facility?

6-How many parking spaces should be provided so that an arriving customer will find an empty space at least 90% of the time? (let s be the desired number of parking spaces)