Processes P1, P2 and P3 arrive at time 0 in that order with burst times 5, 3 and 1 ms. Under round robin with a quantum of 2 ms, what is the average turnaround time?
Correct answer C. 7.33 ms
Explanation
The schedule is P1 0-2, P2 2-4, P3 4-5 (done), P1 5-7, P2 7-8 (done), P1 8-9 (done). Completion times are P1 9, P2 8 and P3 5, and since all arrive at 0 these are the turnaround times, averaging 22 / 3, about 7.33 ms. The value 4.33 ms is the average waiting time. Short P3 finishes early, which is round robin's strength.
Answer checked How we write and check questions
Discussion