Please someone explain how to do this.

4. Compute the average response time when running three jobs of length 10, 20, 30 seconds using shortest job first scheduling. Assume the jobs arrive at the same time. 5. Compute the average turnaround time when running three jobs of length 10, 20, 30 seconds using shortest job first scheduling. Assume the jobs arrive at the same time. 6. Compute the average response time when running three jobs of length 20, 30, 10 seconds using FIFO scheduling. Assume the jobs arrive at almost exactly the same time, but that the jobs arrive in the listed order (in other words, 20 before 30 before 10). 7. Compute the average turnaround time when running three jobs of length 20, 30, 10 using FIFO scheduling. Use the same assumptions about arrival as in the previous