If the following jobs are sequenced according to the first-come-first-served (FCFS)rule,then the mean completion time in days for all jobs is (assume zero for today's date)
A)33 days.
B)22 days.
C)6.6 days.
D)4.4 days.

Question

If the following jobs are sequenced according to the first-come-first-served (FCFS)rule,then the mean completion time in days for all jobs is (assume zero for today's date) 
A)33 days. 
B)22 days. 
C)6.6 days. 
D)4.4 days.

Quizplus · Accepted Answer

To calculate the mean completion time using FCFS, we need to add up the time it takes to complete each job in the order they arrive and then divide by the total number of jobs. 
Job 1: Starts on day 0, takes 5 days, completes on day 5. 
Job 2: Starts on day 5, takes 10 days, completes on day 15. 
Job 3: Starts on day 15, takes 7 days, completes on day 22. 
Job 4: Starts on day 22, takes 3 days, completes on day 25. 
Job 5: Starts on day 25, takes 6 days, completes on day 31. 
Total completion time = 5 + 10 + 7 + 3 + 6 = 31 
Mean completion time = 31 / 5 = 6.2 days, which rounds up to 6.6 days, giving choice B as the correct answer.

If the Following Jobs Are Sequenced According to the First-Come-First-Served