Question

Draw a Gantt chart that shows the completion times for each process
using first-come, first-served CPU scheduling.
120 60 180 50 300

Answer 1

To create a Gantt chart based on the provided process completion times using first-come, first-served (FCFS) CPU scheduling, we first need to identify the processes and their respective burst times. In your case, let's assume you have five processes with the following burst times:

- Process 1: 120 units
- Process 2: 60 units
- Process 3: 180 units
- Process 4: 50 units
- Process 5: 300 units

**Steps:**

1. **Calculate the completion time for each process:**
- **Process 1:** Completes at time 120.
- **Process 2:** Completes at time 120 + 60 = 180.
- **Process 3:** Completes at time 180 + 180 = 360.
- **Process 4:** Completes at time 360 + 50 = 410.
- **Process 5:** Completes at time 410 + 300 = 710.

2. **Build the Gantt chart:**

```
| P1 | P2 | P3 | P4 | P5 |
0 120 180 360 410 710
```

**Interpretation of the Gantt Chart:**

- **P1** starts at time 0 and runs for 120 time units, finishing at time 120.
- **P2** starts right after P1, at time 120, and runs for 60 time units, finishing at time 180.
- **P3** starts at time 180 and runs for 180 time units, finishing at time 360.
- **P4** starts at 360 and runs for 50 time units, finishing at time 410.
- **P5** starts at time 410 and runs for 300 time units, finishing at time 710.

The completion times for each process are as follows:

- **P1:** 120
- **P2:** 180
- **P3:** 360
- **P4:** 410
- **P5:** 710

This Gantt chart illustrates the order of process execution and their completion timings.