Start learning 50% faster. Sign in now
LRU page replacement works by replacing the page that has not been used for the longest time. For the reference string 4, 2, 4, 1, 5, 2, 3, 4 with 3 frames, the page faults occur as follows: • Insert 4 (fault), Insert 2 (fault), Access 4 (hit), Insert 1 (fault), Insert 5 (fault, replace 4), Access 2 (hit), Insert 3 (fault, replace 1), Access 4 (fault, replace 5). Thus, there are 6 page faults in total. LRU minimizes page faults compared to other algorithms by always keeping the most recently used pages in memory. Why other options are wrong: A) 3 faults would require the reference string to contain repeated pages with no replacements. B) 5 faults underestimate the replacements required after the first few frames fill up. D) 7 faults occur in algorithms with more aggressive replacements like FIFO. E) 8 faults assume no page hits at all, which is incorrect since some pages are reused before replacement.
24 ? 14 16 39 88.5
...13 182 303 384 433 ?
...60000 2400 120 8 0.8 ?
...2342 2223 2090 1943 1782 ?
...86 36 ? 7 7.5 0.75
7 12 33 ? 635 3804
...219 365 511 ? 803 949
...729 512 343 216 125 ?
...Direction: Which of the following will replace ‘?’ in the given question?
2, ‘?’, 46, 136, 311, 605, 1086
979.001 + 4.0087× 82.79 = ?
...