For the following list of processes, the average turnaround time and average…
2025
For the following list of processes, the average turnaround time and average waiting time using FCFS algorithm is :
Process | Arrival Time (ms) | Execution Time (ms) |
P1 | 6 | 24 |
P2 | 0 | 3 |
P3 | 3 | 3 |
- A.
Average Turnaround time 30 ms and Average Waiting Time 4.5 ms
- B.
Average Turnaround time 13 ms and Average Waiting Time 3 ms
- C.
Average Turnaround time 10 ms and Average Waiting Time 0 ms
- D.
Average Turnaround time 24 ms and Average Waiting Time 0 ms
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Correct answer: C
In FCFS scheduling, processes are executed in the order of their arrival times: P2 (0ms), P3 (3ms), and P1 (6ms).
Completion Times: P2 finishes at 3ms, P3 finishes at 6ms (3+3), and P1 finishes at 30ms (6+24).
Turnaround Time (Completion - Arrival): P2=3ms, P3=3ms, P1=24ms. Average = (3+3+24)/3 = 10ms.
Waiting Time (Turnaround - Execution): All processes start immediately upon arrival or when the previous one finishes, resulting in 0ms waiting time for each. Average = 0ms.