Help with Information systems

I have done all but MOST Important question 3  if you answer all correctly I have more work for you soon.  Yes this is a test :-)

For problems 1 and 2, a computer has the following four processes that have arrived in the ready queue in the sequence shown below. NOTE: There are no mandatory time outs required.

• Process 1 has a run time of 30 seconds, a priority of 1, and it will require 15 seconds of I/O after 10 seconds of execution.
• Process 2 has a run time of 20 seconds, a priority of 2, and it will require 10 seconds of I/O after 5 seconds of execution.
• Process 3 has a run time of 25 seconds and a priority of 2.
• Process 4 has a run time of 10 seconds and a priority of 1.

1. (2 points) If the Round Robin Scheduling algorithm is used, which process completes first and why?

2. (2 points) If the Non-preemptive Priority Scheduling algorithm is used, which process completes second and why?

3. (3 points) Explain the trade-offs between contiguous, noncontiguous linked, and noncontiguous indexed file allocation. In particular, note the effect on sequential and random access methods.

 MOST IMPORTANT

4. (3 points) Using a variable-partitioned multiprogramming memory, which of the four holes shown below will be used to satisfy a 45 KB program requirement under the conditions of:

___ First-fit
___ Best-fit
___ Worst-fit