Consider the following set of five processes where arrival is the time the process became ready, T is the total execution time, and E is the external priority. Assume that execution starts immediately at time 0 and there is no context switch overhead.

Process ---Arrival time------ T-------- E

p0 --------------- 0 -------------80------ 9

p1 ---------------15 -------------25 ------10

p2 ---------------15 -------------15 -------9

p3 ----------------85 ------------25 ------10

p4 ----------------90 ------------10 ------11

For the following scheduling disciplines, draw Gantt charts showing when each of the five processes executes. (In the case of a tie, assume that the process with the lower process number executes first.) Calculate the average waiting time for each of the scheduling disciplines.

a) FIFO

b) SJF

c) SRT

d) RR (quantum = 10)