Consider the following page reference string and answer the following questions (3 points). Assume the primary memory is initially unloaded. 1,2, 3, 1, 4, 2, 5, 2, 1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 1. 2 a. For a FIFO page replacement algorithm with 4 frames, how many page faults are generated? Show work. b. For a LRU page replacement algorithm with 4 frames, how many page faults are generated? Show work. c. For the Optimal page replacement algorithm with 4 frames, how many page faults are generated? Show work. Consider a demand-paging system with the following time-measured utilizations: CPU utilization | 20 % Paging disk 97.9 % Other I/O devices 5 % For each of the following, say weather it will (or is likely to) improve CPU utilization. Explain your answers. (2 points) a) Increase the degree of multiprogramming b) Install more main memory c) Increase the page size d) Install a faster CPU