Data gathered by the ticket office indicates that during peak times, such as weekends and holidays, visitors arrive at an average rate of 40 per hour, with inter-arrival times having a coefficient of variation of 1. The process of serving a visitor takes an average of 5 minutes, and this time follows a normal distribution, with a standard deviation of 2 minutes. It is assumed that every visitor joining the queue will remain until they have purchased a ticket and entered the castle