Virginia's Ron McPherson Electronics Corporation retains a service crew to repair machine breakdowns that occur on an average of $2=2$ per $8-$hour workday $($approximately Poisson in nature$).$ The crew can service an average of $10$ machines per workday, with a repair time distribution that resembles the negative exponential distribution. a$)$ The utilization rate of this service system $=20($round your response to two decimal places$).$ b$)$ The average downtime for a broken machine $=$ days $($round your response to two decimal places$).$