Question In a small barber shop, only one customer can get hair cut and washing services while another customer can wait in a chair. Any other arriving customers have to queue outside as there is only one chair in the shop. The customers arrive randomly at 3.5 per hour according to poison distribution. The service is exponential and takes 10 minutes for cutting and 5 minutes for washing in the average. Find the probability that an arriving customer will have to wait outside. ii) What is the average number of customers waiting outside? iii) On average, how long does a customer wait in the service system? [6 marks) To avoid customer dissatisfaction, the barber must ensure no customer is waiting outside (L,