GATE 2018 Previous Year Paper Solution Question 10 – Computer Science

In this video question which was asked in the exam of GATE 2018 is discussed.
Question :- Consider a process executing on an operating system that uses demand paging. The average time for a memory access in the system is M units if the corresponding memory page is available in memory, and D units if the memory access causes a page fault. It has been experimentally measured that the average time taken for a memory access in the process is X units.
Which one of the following is the correct expression for the page fault rate experienced by the process ?
A. (D-M)⁄(X-M)
B. (X-M)⁄(D-M)
C. (D-X)⁄(D-M)
D. (X-M)⁄(D-X)

Solution is given in the video.