please no chatgpt answer . Consider a demand-paging system with a paging disk that has an average access and transfer time of 20 milliseconds. Addresses are translated through a page table in main memory, with an access time of 1 microsecond per memory access. Thus, each memory reference through the page table takes two accesses. To improve this time, we have added an associative memory that reduces access time to one memory reference, if the page-table entry is in the associative memory. Assume that 80 percent of the accesses are in the associative memory and that, of those remaining, 10 percent (or 2 percent of the total) cause page faults. What is the effective memory access time? Consider the following page reference string: 1, 2, 3, 4, 2, 1, 5, 6, 2, 1, 2, 3, 7, 6, 3, 2, 1, 2, 3, 6. Assuming demand paging with four frames, Show which pages are resident under the LRU, FIFO, and Optimal replacement algorithms by filling out the following tables. How many page faults would occur for each of the replacement algorithms? Please provide your answers in the tables below: LRU Reference String 1 2 3 4 2 1 5 6 2 1 2 3 7 6 3 2 1 2 3 6 Frame 0                                         Frame 1                                         Frame 2                                         Page fault                                           The number of page faults for the LRU is _________   Optimal Reference String 1 2 3 4 2 1 5 6 2 1 2 3 7 6 3 2 1 2 3 6 Frame 0                                         Frame 1                                         Frame 2                                         Page fault                                           The number of page faults for the FIFO is _________   Optimal Reference String 1 2 3 4 2 1 5 6 2 1 2 3 7 6 3 2 1 2 3 6 Frame 0                                         Frame 1                                         Frame 2                                         Page fault                                           The number of page faults for the Optimal is ________