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: Time slicing is not used, therefore, there are no mandatory time outs.

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

(HINT for problems 1 and 2: Review Module 6 section 2.1.2 for the definitions of these scheduling algorithms and Self-Assessment problems 1-4.)

1. (2 points) If the Round Robin Scheduling algorithm is used, which process completes second and why? At what time does it complete?

2. (2 points) If the Round Robin with Priority Queues Scheduling algorithm is used, which process completes second and why? At what time does it complete?

3. (3 points) Explain the trade-offs between contiguous, noncontiguous linked, and noncontiguous indexed file allocation. In particular, note if each can be efficiently used for sequential and random access methods.

4. (3 points) Using a variable-partitioned multiprogramming memory, which of the four holes shown below will be used to satisfy a 55 KB program requirement under the conditions of:

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