Operating Systems Assignment 3 Answer the following question How many page faults occur for the following reference string, with four page frames? 1,4,7,5,5,2,9,4,2,7,4,6,2,3,7,8,9,4,8,8,2,9,4,6,7,1,6,2,8,8 Consider the following page replacement algorithms: i) Optimal algorithm. ii) FIFO iii) LRU