Page Fault Count for an LRU Replacement Policy with Four Frames

Question 1

In a virtual memory system that uses the Least Recently Used (LRU) page replacement policy, calculate the number of page faults. Number of frames = 4 Reference strings: 1, 4, 3, 2, 1, 2, 6, 2, 1, 5, 6, 3, 2, 4, 5