ISRO-2013-65

Question

Consider the list of page references in the time line as below:

9  6  2  3  4  4  4  4  3  4  4  2  5  8  6  8  5  5  3  2  3  3  9  6  2  7

What is the working set at the penultimate page reference if ∆ is 5?

• A. {8, 5, 3, 2, 9, 6}
• B. {4, 3, 6, 2, 5}
• C. {3, 9, 6, 2, 7}
• D. {3, 9, 6, 2}

Comments

d is correct option

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working set at the penultimate(second from the last) page reference if ∆ is 5.

9 6 2 3 4 4 4 4 3 4 4 2 5 8 6 8 5 5 3 2 3 3 9 6 2 7

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Please check my answer below

Answer 1

Here Working set window Size=5=Delta

The working-set window is a moving window.

At each memory reference, a new reference appears at one end and the oldest reference drops off the other end.

A page is in the working set if it is referenced anywhere in the working-set window. (Galvin;;Don't worry read the last paragraph  to understand it simply)

 

Now As Told here penultimate reference (means except last reference) So take 5 page reference from end of the given list of references from the question except last reference. i.e.7 They are {3,3,9,6,2} in Working Set Window So the Working Set is {3,9,6,2}. So, option D is the Ans.

Note

Working Set Window::-- Examines the most recent Delta no. of page references.

Working Set::--Set of unique pages in most recent Delta page references.

Comments

Here Working set window size=Delta=10

Answer 2

I think working set at the penultimate ( second from the last ) page reference would be

{3, 9, 6, 2 }

And finally at last

{ 3, 9, 6, 2, 7 }

Comments

if penultimate mean that your answer is correct and i assumed it as last working set

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second last will be{2,3,6,9}
 so (D)isanswer

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working set will be{3,9,6,2}
 so (D)isanswer

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sorry bro... now updated ..

Answer 3

Penultimate page reference means second last page reference. Hence answer will be D. (3,9,6,2)

 

Working sets are as below:

9 - {9}

6 - {9,6}

2 - {9,6,2}

3 - {9,6,2,3}

4 - {9,6,2,3,4}

4 - {6,2,3,4}

4 - {2,3,4}

4 - {3,4}

3 - {3,4}

4 - {3,4}

4 - {3,4}

2 - {3,4,2}

5 - {3,4,2,5}

8 - {2,4,5,8}

6 - {2,4,5,8,6}

8 - {2,5,8,6}

5 - {5,8,6}

5 - {5,8,6}

3 - {3,5,8,6}

2 - {2,3,5,8}

3 - {2,3,5}

9 - {2,3,9}

6 - {2,3,9,6}

2 - {3,9,6,2}

7 - {3,9,6,2,7}

Comments

please visit the link

http://cs.uttyler.edu/Faculty/Rainwater/COSC3355/Animations/workingset.htm

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thanx bro

Answer 4

Answer: option D

Penultimate means in second last working set model.

Please visit this link for more information.

http://cs.uttyler.edu/Faculty/Rainwater/COSC3355/Animations/workingset.htm