Given page stream using $3-$page slots, complete the following page replacement cases using the required algorithm and indicate the number of page faults for each case. If the page reference results in equal replacement oppurtunity on mulitple slots for required algorithm is currently inapplicable$),$ we will apply the FIFO to current page reference.

$(5$pt$)$ Optimal $($OPT$),$ there are $\_\_\_$ page faults.

$(5$pt$)$ Least Recently Used $($LRU$),$ there are $\_\_\_\_$

page faults.

$(5$pt$)$ Least Frequently Used $($LFU$),$ there are $\_\_\_\_$

page faults.