A clinic has only one dentist. During working days, the traffic is uniformly busy with patients arriving at the rate of $6$ patients per hour. The doctor$$s service time is $6$ minutes. $($Please keep three digits after the decimal and do not omit $0$ before the decimal, good example: $0\mathrm{.}132)$

What is the probability that the clinic is empty $($except for the dentist$)?$

What is the average number of patients in the waiting room?

What is the average time $($in minutes$)$ a patient spends in the office $($wait plus service$)?$

What is the probability that the clinic has exactly two patients?