Assume that the page reference string is made by recording the virtual page number every 2 ticks while a process is executing. Assume that P1, P2, and P3 arrived just before t=0 with the arriving order of {P1, P2, P3}. P1 and P2 execute PA, and P3 executes PB. Assume that all processes execute the same program, and their page reference strings are not the same. Let P1 has the following page reference string: {7, 8, 8, 21, 22, 8, 21, 22, 21, 22, 9}. P2has their own page reference string shown as: {7, 8, 8, 21, 22, 21, 22, 9}. P3 will have the page reference string shown below: {6, 6, 6, 7, 8}. Assume that the system needs 5 ticks to handle each page fault, and they are handled in a first-come-first-serve manner. Draw a Gantt chart illustrating the scheduling of these processes and find the number of page faults for each process if a Round-Robin non-preemptive scheduling with a time quantum of 4 ticks is used. Note that each process has a working set of 3 pages, and the page replacement algorithm is FIFO. Show the contents of the progressing working sets.