FCFS(FIRST COME FIRST SERVED) question

Here are 13 questions on FCFS(FIRST COME FIRST SERVED) process scheduling algorithms, .Each question is presented in a table format, followed by the solution with Gantt charts, average turnaround time (TAT), and average waiting time (WT).

Jump To Question

Question 11 :using the given table, find the average Turn Around Time and Waiting Time of following processes using FCFS(FIRST COME FIRST SERVED) process scheduling algorithm?

Process Arrival Time (AT) Burst Time (BT)
P1 0 3
P2 2 6
P3 4 4
P4 6 5
P5 8 2
P6 9 7

Solution

Formulas :

Turn Around Time (TAT) = Completion Time (CT) - Arrival Time (AT)

Waiting Time (WT) = Turn Around Time (TAT) - Burst Time (BT)

Gantt Chart

FCFS SCHEDULING | Question 11 Solution | Gantt Chart
Process Arrival Time (AT) Burst Time (BT) Completion Time (CT) Turn Around Time (TAT) Waiting Time (WT)
P1 0 3 3 3 0
P2 2 6 9 7 1
P3 4 4 13 9 5
P4 6 5 18 12 7
P5 8 2 20 12 10
P6 9 7 27 18 11

Formulas:

  • Average Turn Around Time (Average TAT) = Σ(TAT) / Number of Processes
  • Average Waiting Time (Average WT) = Σ(WT) / Number of Processes

Average Turn Around Time (TAT) = (TAT1 + TAT2 + TAT3 + TAT4 + TAT5 + TAT6) / 6 = (3 + 7 + 9 + 12 + 12 + 18) / 6 = 61 / 6 = 10.17

Average Waiting Time (WT) = (WT1 + WT2 + WT3 + WT4 + WT5 + WT6) / 6 = (0 + 1 + 5 + 7 + 10 + 11) / 6 = 34 / 6 = 5.67

Question 12

find the average Turn Around Time and Waiting Time of following processes using FCFS(FIRST COME FIRST SERVED) process scheduling algorithm?

Process Arrival Time (AT) Burst Time (BT)
P1 0 5
P2 1 9
P3 2 6
P4 3 7
P5 5 4
P6 6 3

Solution

Formulas :

Turn Around Time (TAT) = Completion Time (CT) - Arrival Time (AT)

Waiting Time (WT) = Turn Around Time (TAT) - Burst Time (BT)

Gantt Chart

FCFS SCHEDULING | Question 12 Solution | Gantt Chart
Process Arrival Time (AT) Burst Time (BT) Completion Time (CT) Turn Around Time (TAT) Waiting Time (WT)
P1 0 5 5 5 0
P2 1 9 14 13 4
P3 2 6 20 18 12
P4 3 7 27 24 17
P5 5 4 31 26 22
P6 6 3 34 28 25

Formulas:

  • Average Turn Around Time (Average TAT) = Σ(TAT) / Number of Processes
  • Average Waiting Time (Average WT) = Σ(WT) / Number of Processes

Average Turn Around Time (TAT) = (TAT1 + TAT2 + TAT3 + TAT4 + TAT5 + TAT6) / 6 = (5 + 13 + 18 + 24 + 26 + 28) / 6 = 114 / 6 = 19.00

Average Waiting Time (WT) = (WT1 + WT2 + WT3 + WT4 + WT5 + WT6) / 6 = (0 + 4 + 12 + 17 + 22 + 25) / 6 = 80 / 6 = 13.33

Problem 13

find the average Turn Around Time and Waiting Time of following processes using FCFS(FIRST COME FIRST SERVED) process scheduling algorithm?

Process Arrival Time (AT) Burst Time (BT)
P1 0 2
P2 1 4
P3 2 8
P4 3 3
P5 4 7
P6 5 6

Solution

Formulas :

Turn Around Time (TAT) = Completion Time (CT) - Arrival Time (AT)

Waiting Time (WT) = Turn Around Time (TAT) - Burst Time (BT)

Gantt Chart

FCFS SCHEDULING | Question 13 Solution | Gantt Chart
Process Arrival Time (AT) Burst Time (BT) Completion Time (CT) Turn Around Time (TAT) Waiting Time (WT)
P1 0 2 2 2 0
P2 1 4 6 5 1
P3 2 8 14 12 4
P4 3 3 17 14 11
P5 4 7 24 20 13
P6 5 6 30 25 19

Formulas:

  • Average Turn Around Time (Average TAT) = Σ(TAT) / Number of Processes
  • Average Waiting Time (Average WT) = Σ(WT) / Number of Processes

Average Turn Around Time (TAT) = (TAT1 + TAT2 + TAT3 + TAT4 + TAT5 + TAT6) / 6 = (2 + 5 + 12 + 14 + 20 + 25) / 6 = 78 / 6 = 13.00

Average Waiting Time (WT) = (WT1 + WT2 + WT3 + WT4 + WT5 + WT6) / 6 = (0 + 1 + 4 + 11 + 13 + 19) / 6 = 48 / 6 = 8.00

Problem 14

find the average Turn Around Time and Waiting Time of following processes using FCFS(FIRST COME FIRST SERVED) process scheduling algorithm?

Process Arrival Time (AT) Burst Time (BT)
P1 0 6
P2 1 3
P3 2 5
P4 3 7
P5 5 4
P6 6 2

Solution

Formulas :

Turn Around Time (TAT) = Completion Time (CT) - Arrival Time (AT)

Waiting Time (WT) = Turn Around Time (TAT) - Burst Time (BT)

Gantt Chart

FCFS SCHEDULING | Question 14 Solution | Gantt Chart
Process Arrival Time (AT) Burst Time (BT) Completion Time (CT) Turn Around Time (TAT) Waiting Time (WT)
P1 0 6 6 6 0
P2 1 3 9 8 5
P3 2 5 14 12 7
P4 3 7 21 18 11
P5 5 4 25 20 16
P6 6 2 27 21 19

Formulas:

  • Average Turn Around Time (Average TAT) = Σ(TAT) / Number of Processes
  • Average Waiting Time (Average WT) = Σ(WT) / Number of Processes

Average Turn Around Time (TAT) = (TAT1 + TAT2 + TAT3 + TAT4 + TAT5 + TAT6) / 6 = (6 + 8 + 12 + 18 + 20 + 21) / 6 = 85 / 6 = 14.17

Average Waiting Time (WT) = (WT1 + WT2 + WT3 + WT4 + WT5 + WT6) / 6 = (0 + 5 + 7 + 11 + 16 + 19) / 6 = 58 / 6 = 9.67

Problem 15

find the average Turn Around Time and Waiting Time of following processes using FCFS(FIRST COME FIRST SERVED) process scheduling algorithm?

Process Arrival Time (AT) Burst Time (BT)
P1 0 7
P2 2 2
P3 4 6
P4 6 5
P5 8 3
P6 10 8

Solution

Formulas :

Turn Around Time (TAT) = Completion Time (CT) - Arrival Time (AT)

Waiting Time (WT) = Turn Around Time (TAT) - Burst Time (BT)

Gantt Chart

FCFS SCHEDULING | Question 15 Solution | Gantt Chart
Process Arrival Time (AT) Burst Time (BT) Completion Time (CT) Turn Around Time (TAT) Waiting Time (WT)
P1 0 7 7 7 0
P2 2 2 9 7 5
P3 4 6 15 11 5
P4 6 5 20 14 9
P5 8 3 23 15 12
P6 10 8 31 21 13

Formulas:

  • Average Turn Around Time (Average TAT) = Σ(TAT) / Number of Processes
  • Average Waiting Time (Average WT) = Σ(WT) / Number of Processes

Average Turn Around Time (TAT) = (TAT1 + TAT2 + TAT3 + TAT4 + TAT5 + TAT6) / 6 = (7 + 7 + 11 + 14 + 15 + 21) / 6 = 75 / 6 = 12.50

Average Waiting Time (WT) = (WT1 + WT2 + WT3 + WT4 + WT5 + WT6) / 6 = (0 + 5 + 5 + 9 + 12 + 13) / 6 = 44 / 6 = 7.33

Problem 16

find the average Turn Around Time and Waiting Time of following processes using FCFS(FIRST COME FIRST SERVED) process scheduling algorithm?

Process Arrival Time (AT) Burst Time (BT)
P1 1 4
P2 2 5
P3 3 6
P4 4 7
P5 5 8
P6 6 9

Solution

Formulas :

Turn Around Time (TAT) = Completion Time (CT) - Arrival Time (AT)

Waiting Time (WT) = Turn Around Time (TAT) - Burst Time (BT)

Gantt Chart

FCFS SCHEDULING | Question 16 Solution | Gantt Chart
Process Arrival Time (AT) Burst Time (BT) Completion Time (CT) Turn Around Time (TAT) Waiting Time (WT)
P1 1 4 5 4 0
P2 2 5 10 8 3
P3 3 6 16 13 7
P4 4 7 23 19 12
P5 5 8 31 26 18
P6 6 9 40 34 25

Formulas:

  • Average Turn Around Time (Average TAT) = Σ(TAT) / Number of Processes
  • Average Waiting Time (Average WT) = Σ(WT) / Number of Processes

Average Turn Around Time (TAT) = (TAT1 + TAT2 + TAT3 + TAT4 + TAT5 + TAT6) / 6 = (4 + 8 + 13 + 19 + 26 + 34) / 6 = 104 / 6 = 17.33

Average Waiting Time (WT) = (WT1 + WT2 + WT3 + WT4 + WT5 + WT6) / 6 = (0 + 3 + 7 + 12 + 18 + 25) / 6 = 65 / 6 = 10.83

Problem 17

find the average Turn Around Time and Waiting Time of following processes using FCFS(FIRST COME FIRST SERVED) process scheduling algorithm?

Process Arrival Time (AT) Burst Time (BT)
P1 0 4
P2 1 6
P3 2 8
P4 3 3
P5 4 5
P6 5 2

Solution

Formulas :

Turn Around Time (TAT) = Completion Time (CT) - Arrival Time (AT)

Waiting Time (WT) = Turn Around Time (TAT) - Burst Time (BT)

Gantt Chart

FCFS SCHEDULING | Question 17 Solution | Gantt Chart
Process Arrival Time (AT) Burst Time (BT) Completion Time (CT) Turn Around Time (TAT) Waiting Time (WT)
P1 0 4 4 4 0
P2 1 6 10 9 3
P3 2 8 18 16 8
P4 3 3 21 18 15
P5 4 5 26 22 17
P6 5 2 28 23 21

Formulas:

  • Average Turn Around Time (Average TAT) = Σ(TAT) / Number of Processes
  • Average Waiting Time (Average WT) = Σ(WT) / Number of Processes

Average Turn Around Time (TAT) = (TAT1 + TAT2 + TAT3 + TAT4 + TAT5 + TAT6) / 6 = (4 + 9 + 16 + 18 + 22 + 23) / 6 = 92 / 6 = 15.33

Average Waiting Time (WT) = (WT1 + WT2 + WT3 + WT4 + WT5 + WT6) / 6 = (0 + 3 + 8 + 15 + 17 + 21) / 6 = 64 / 6 = 10.67

Problem 18

find the average Turn Around Time and Waiting Time of following processes using FCFS(FIRST COME FIRST SERVED) process scheduling algorithm?

Process Arrival Time (AT) Burst Time (BT)
P1 0 4
P2 1 5
P3 2 6
P4 3 7
P5 4 8
P6 5 9

Solution

Formulas :

Turn Around Time (TAT) = Completion Time (CT) - Arrival Time (AT)

Waiting Time (WT) = Turn Around Time (TAT) - Burst Time (BT)

Gantt Chart

FCFS SCHEDULING | Question 18 Solution | Gantt Chart
Process Arrival Time (AT) Burst Time (BT) Completion Time (CT) Turn Around Time (TAT) Waiting Time (WT)
P1 0 4 4 4 0
P2 1 5 9 8 3
P3 2 6 15 13 7
P4 3 7 22 19 12
P5 4 8 30 26 18
P6 5 9 39 34 25

Formulas:

  • Average Turn Around Time (Average TAT) = Σ(TAT) / Number of Processes
  • Average Waiting Time (Average WT) = Σ(WT) / Number of Processes

Average Turn Around Time (TAT) = (TAT1 + TAT2 + TAT3 + TAT4 + TAT5 + TAT6) / 6 = (4 + 8 + 13 + 19 + 26 + 34) / 6 = 104 / 6 = 17.33

Average Waiting Time (WT) = (WT1 + WT2 + WT3 + WT4 + WT5 + WT6) / 6 = (0 + 3 + 7 + 12 + 18 + 25) / 6 = 65 / 6 = 10.83

Problem 19

find the average Turn Around Time and Waiting Time of following processes using FCFS(FIRST COME FIRST SERVED) process scheduling algorithm?

Process Arrival Time (AT) Burst Time (BT)
P1 0 3
P2 1 4
P3 2 5
P4 3 6
P5 4 7
P6 5 8

Solution

Formulas :

Turn Around Time (TAT) = Completion Time (CT) - Arrival Time (AT)

Waiting Time (WT) = Turn Around Time (TAT) - Burst Time (BT)

Gantt Chart

FCFS SCHEDULING | Question 19 Solution | Gantt Chart
Process Arrival Time (AT) Burst Time (BT) Completion Time (CT) Turn Around Time (TAT) Waiting Time (WT)
P1 0 3 3 3 0
P2 1 4 7 6 2
P3 2 5 12 10 5
P4 3 6 18 15 9
P5 4 7 25 21 14
P6 5 8 33 28 20

Formulas:

  • Average Turn Around Time (Average TAT) = Σ(TAT) / Number of Processes
  • Average Waiting Time (Average WT) = Σ(WT) / Number of Processes

Average Turn Around Time (TAT) = (TAT1 + TAT2 + TAT3 + TAT4 + TAT5 + TAT6) / 6 = (3 + 6 + 10 + 15 + 21 + 28) / 6 = 83 / 6 = 13.83

Average Waiting Time (WT) = (WT1 + WT2 + WT3 + WT4 + WT5 + WT6) / 6 = (0 + 2 + 5 + 9 + 14 + 20) / 6 = 50 / 6 = 8.33

Problem 20

find the average Turn Around Time and Waiting Time of following processes using FCFS(FIRST COME FIRST SERVED) process scheduling algorithm?

Process Arrival Time (AT) Burst Time (BT)
P1 0 4
P2 1 5
P3 2 6
P4 3 7
P5 4 8
P6 5 9

Solution

Formulas :

Turn Around Time (TAT) = Completion Time (CT) - Arrival Time (AT)

Waiting Time (WT) = Turn Around Time (TAT) - Burst Time (BT)

Gantt Chart

FCFS SCHEDULING | Question 20 Solution | Gantt Chart
Process Arrival Time (AT) Burst Time (BT) Completion Time (CT) Turn Around Time (TAT) Waiting Time (WT)
P1 0 4 4 4 0
P2 1 5 9 8 3
P3 2 6 15 13 7
P4 3 7 22 19 12
P5 4 8 30 26 18
P6 5 9 39 34 25

Formulas:

  • Average Turn Around Time (Average TAT) = Σ(TAT) / Number of Processes
  • Average Waiting Time (Average WT) = Σ(WT) / Number of Processes

Average Turn Around Time (TAT) = (TAT1 + TAT2 + TAT3 + TAT4 + TAT5 + TAT6) / 6 = (4 + 8 + 13 + 19 + 26 + 34) / 6 = 104 / 6 = 17.33

Average Waiting Time (WT) = (WT1 + WT2 + WT3 + WT4 + WT5 + WT6) / 6 = (0 + 3 + 7 + 12 + 18 + 25) / 6 = 65 / 6 = 10.83