A system has four frames for storing the pages of a process in the physical memory. Assume all the four frames are initially empty. The system uses optimal and least recently used (LRU) page replacement policies to handle the page fault. When the system processing the below given page reference string. 4.7, 6, 1, 7, 6, 1, 2, 7, 2, 3, 4, 2, 1, 4, 2 i) Calculate the number of page faults and page hit ii) Calculate the page fault ratio and page hit ratio.