a) Describe THREE events that could cause a process in running state transiting to a different state. (3 marks) b) Consider a UNIX file system with 10 direct pointers, 1 single-indirect pointer, and 1 double-indirect pointer in the i-node. Assume that the size of each disk block is 8KB and each pointer to a disk block requires 4 bytes. What is the largest possible file that can be supported with this design? Show the expression. (3 marks) c) A disadvantage of both Interrupt driven I/O and Programmed I/O is that data must travel over the system bus twice: first to the CPU and then again to its destination. Name one I/O technique which does NOT need this to happen AND explain why. (3 marks) d) Suppose there are four processes in the ready queue: P1, P2, P3, and P4. For each process, the CPU burst time and priority are given below. Suppose lower numbers represent high priority and there is no I/O operation involved in these processes. Show how these four processes are dispatched using a Priority Scheduling algorithm. AND identify one key problem with this scheduling algorithm. Process Burst Time Priority 15 2 2 7 3 2 4 10 3 (6 marks) 1 4 e) Suppose that there are 3 free page frames (1, 2, 3) and 5 virtual pages named as A, B, C, D, E. Given the page reference stream as: ABCADA BEBA Show the page replacement sequence using the LRU Page Replacement algorithm