| Process | Arrival Time | Burst Time |
| P1 | 0 | 8 |
| P2 | 1 | 4 |
| P3 | 2 | 9 |
| P4 | 3 | 5 |
Now we have to calculate average waiting time for schedule:
avg waiting time = wt(P1 + P2 + P3 + P4 )/number of process.
ie. (9 + 0 + 15 + 2) / 4
= 26 / 4
= 6.5
So, option (A) is correct.
1. In FIFO algorithm 15 page fault will occur.
2. In LIFO algorithm 11 page fault will occur.
3. In LRU algorithm 12 page fault will occur.
4.In optimal algorithm 9 page fault will occur.
So, option (D) will be correct.