Problem on Contiguous Memory allocation

Question

There are 5 processes in a job queue

Process	Memory	Required Time
P1	600kb	10 ms
P2	1000kb	5 ms
P3	300kb	20 ms
P4	700kb	8 ms
P5	500kb	15 ms

Memory is byte addressable

If the size of the memory is 2000 kb and contiguous memory allocation is used, then after 30 ms, which processes will be in memory?

(A) P4,P5 only

(B) P1, P2 only

(C) P3, P4 only

(D) None of these

Answer 1

Answer will be D) None of these

Time 0 Ms : Schedule P1, P2, P3 (Memory still you have 100 KB)

Time 5 Ms : P2 Get completed then you will have memory (1100 KB), Now you can schedule P4, (memory still you have is 400 KB)

Time 10 Ms: P1 get completed the you will have memory (1000 KB), Now you can schedule P5.

Time 13 Ms: P4 will get completed.

Time 20 Ms: P3 will get completed.

Time 25Ms: P5 will get completed.

Time 30Ms: No processor is in the memory.

Comments

how did you conclude that P2 will execute first??