M/M/∞ Queue. Responsive Servers: Consider a queuing system in which arrivals are Poisson with parameter λ for any state of the system and the departure rate for state k is μk for each value of k = 0, 1, ... . Obtain the probability of having k customers in the system as a function of μ and λ, the average number of customers in the system, and the average time spent by a customer in the system.