Question

Assume there is an operating system which utilizes demand paging, and that 20 page requests have passed. Calculate the page fault rate for each of the following numbers of page faults which occured during the last 20 requests.

-4
-7
-10
-15
-18
-19

Answer 1

The page fault rate is calculated by dividing the number of faults by the number of requests and then converting it to a percentage. The rates for 4, 7, 10, 15, 18, and 19 faults out of 20 requests are 20%, 35%, 50%, 75%, 90%, and 95% respectively.

Step-by-step explanation:

The student is asking about calculating the page fault rate in a demand paging system for an operating system. The page fault rate is found by dividing the number of page faults by the number of page requests. Since there are 20-page requests, to find the page fault rate for each scenario, we divide the number of faults (which are 4, 7, 10, 15, 18, and 19 respectively) by 20 and then express it as a percentage.

• For 4-page faults: (4/20) × 100% = 20%
• For 7-page faults: (7/20) × 100% = 35%
• For 10-page faults: (10/20) × 100% = 50%
• For 15-page faults: (15/20) × 100% = 75%
• For 18-page faults: (18/20) × 100% = 90%
• For 19-page faults: (19/20) × 100% = 95%