Consider the following page reference string:

(3 points) 1, 2, 3, 4, 2, 1, 5, 6, 2, 1, 2, 3, 7, 6, 3, 2, 1, 2, 3, 6.

How many page faults would occur for the following replacement algorithms, assuming one, two, three, four, five, six, or seven frames? Remember all frames are initially empty, so your first unique pages will all cost one fault each.

LRU replacement

FIFO replacement

Optimal replacement

Note:kindy use your own words do not copy and paste from other sources!!