To calculate the average turnaround time using Shortest Job First (SJF) scheduling, we first need to understand that in SJF, the process with the smallest burst time is executed first.

Given the data:

Process Arrival Time Burst Time
P1 0 7
P2 1 4
P3 2 9
P4 3 5

First, we arrange the processes according to their arrival times and then burst times. At time 0, P1 arrives with burst time 7. At time 1, P2 arrives with burst time 4, which is less than the remaining time of P1, so P2 is executed first.

The Gantt chart would look like this:

0 P1 1 P2 5 P4 10 P1 17 P3 26

Now, we calculate the turnaround time for each process:

Turnaround time = Completion time - Arrival time

For P1: 17 - 0 = 17
For P2: 5 - 1 = 4
For P3: 26 - 2 = 24
For P4: 10 - 3 = 7

Then, we calculate the average turnaround time:

Average turnaround time = (Turnaround time of P1 + Turnaround time of P2 + Turnaround time of P3 + Turnaround time of P4) / 4

Average turnaround time = (17 + 4 + 24 + 7) / 4 = 13

So, the average turnaround time using SJF is 13. Therefore, the correct answer is b. 13.

Question

To calculate the average turnaround time using Shortest Job First (SJF) scheduling, we first need to understand that in SJF, the process with the smallest burst time is executed first.

Given the data:

Process   Arrival Time   Burst Time
P1        0              7
P2        1              4
P3        2              9
P4        3              5

First, we arrange the processes according to their arrival times and then burst times. At time 0, P1 arrives with burst time 7. At time 1, P2 arrives with burst time 4, which is less than the remaining time of P1, so P2 is executed first.

The Gantt chart would look like this:

0   P1   1   P2   5   P4   10  P1   17  P3   26

Now, we calculate the turnaround time for each process:

Turnaround time = Completion time - Arrival time

For P1: 17 - 0 = 17
For P2: 5 - 1 = 4
For P3: 26 - 2 = 24
For P4: 10 - 3 = 7

Then, we calculate the average turnaround time:

Average turnaround time = (Turnaround time of P1 + Turnaround time of P2 + Turnaround time of P3 + Turnaround time of P4) / 4

Average turnaround time = (17 + 4 + 24 + 7) / 4 = 13

So, the average turnaround time using SJF is 13. Therefore, the correct answer is b. 13.

Knowee AI · Accepted Answer