ISRO | ISRO CS 2018 | Question 65

Determine the number of page faults when references to pages occur in order – 1, 2, 4, 5, 2, 1, 2, 4. Assume that the main memory can accommodate 3 pages and the main memory already has the pages 1 and 2, with page 1 having brought earlier than page 2.(assume LRU algorithm is used)
(A) 3
(B) 4
(C) 5
(D) None of these

Answer: (B)
Explanation: The references to pages occur in order – 1, 2, 4, 5, 2, 1, 2, 4 can be seen in the figure:

So, option (B) is correct.
Quiz of this Question