Observations at an airport with $3$ gates show that the average service time to load$/$unload an

airplane is $17$ minutes $($with an exponential distribution$).$ During the peak hours of operation,

aircraft randomly arrive at a rate of $8\mathrm{.}2/$hour$.$

a$.$ What is the current average wait time for aircraft requiring a gate?

b$.$ What is the probability that $2$ or more aircraft will be parked $($or waiting$)$ at any one time?