Suppose the following jobs are to be executed in a uniprocessor system. Assume…

FCFS schedule and timings (with 1-unit context switch between consecutive jobs):

• Process 1: arrival 0, burst 4 → completes at time 4, turnaround = 4 - 0 = 4

• Process 2: arrival 1, burst 8 → after a 1-unit context switch starts at time 5, completes at time 13, turnaround = 13 - 1 = 12

• Process 3: arrival 3, burst 2 → after context switch starts at time 14, completes at time 16, turnaround = 16 - 3 = 13

• Process 4: arrival 10, burst 6 → after context switch starts at time 17, completes at time 23, turnaround = 23 - 10 = 13

• Process 5: arrival 12, burst 5 → after context switch starts at time 24, completes at time 29, turnaround = 29 - 12 = 17

Average turnaround time:

Average = (4 + 12 + 13 + 13 + 17) / 5 = 59 / 5 = 11.8

Normalized turnaround time for the process with burst 8:

Normalized = turnaround / burst = 12 / 8 = 1.5

CPU efficiency:

Total CPU busy time (sum of bursts) = 4 + 8 + 2 + 6 + 5 = 25

Number of context switches = 4 (one between each consecutive pair), context-switch overhead total = 4 × 1 = 4

Total elapsed time from start to final completion = 29 (includes the context switches)

Efficiency = CPU busy time / total elapsed time = 25 / 29 ≈ 86.2%

Final result: average turnaround time = 11.8, normalized turnaround for the burst-8 process = 1.5, CPU efficiency ≈ 86.2%.