Explanation: P1 starts but is preempted after 20ms when P2 arrivesand has shorter burst time (20ms) than the remaining burst time ofP1 (30 ms) . So, P1 is preempted. P2 runs to completion. At 40ms P3arrives, but it has a longer burst time than P1, so P1 will run. At60ms P4 arrives. At this point P1 has a remaining burst time of 10ms, which is the shortest time, so it continues to run. Once P1finishes, P4 starts to run since it has shorter burst time than P3