Consider an M/M/1 queue in which customers arrive according to a Poisson process with rate λ = 3 and successive service times are independent exponential random variables having a mean of 1/9. Let Pn be the long-run probability that there are exactly n customers in the system. Which of the following statements is true?

Which of the following is NOT a standard assumption of a basic single-server queueing model (M/M/1)?

Consider the M/M/1 queue in which customers arrive according to a Poisson process with rate 3 and successive service times are independent exponential random variables having mean 19. Let Pn be the long-run probability that there are exactly n customers in the system. Then, which of the following statements is true?