Question 9 (15 pts) (Bernoulli trials) Assume a queueing network with a CPU and an IO device. The service time is negative exponentially distributed with mean 1/u, the probability of a job being done at the end of a CPU service slice is po. The job needs service at an I/O device with probability q Let po-0.3; 1/u-6sec; a. b. c. (5 pts) What is the probability that a job needs 10 trips to the CPU? Give both formula and result. (5 pts) What is the expected total CPU time? Give both formula and result. (5 pts) Assume a CPU utilization U-0.80. What is the throughput in jobs per minute? Give both formula and result. 2 Question 9 (15 pts) (Bernoulli trials) Assume a queueing network with a CPU and an IO device. The service time is negative exponentially distributed with mean 1/u, the probability of a job being done at the end of a CPU service slice is po. The job needs service at an I/O device with probability q Let po-0.3; 1/u-6sec; a. b. c. (5 pts) What is the probability that a job needs 10 trips to the CPU? Give both formula and result. (5 pts) What is the expected total CPU time? Give both formula and result. (5 pts) Assume a CPU utilization U-0.80. What is the throughput in jobs per minute? Give both formula and result. 2