1. An operating system that does not support multithreading cannot simultaneously utilize multiple processors (CPUs). Is this statement true? Please explain.

2. In order for a single-CPU computer system to support multitasking (for example, allowing the user to open up multiple windows), the operating system must be able to support multithreading. Is this a true statement? please explain

3. UNIX operating system uses zombie state to keep track of processes that finished execution. Microsoft Windows operating system does not have zombie as a process state. Will it be useful to add zombie state to Microsoft Windows Operating system?

4. A process is allocated 1 CPU second at any given point of time. The interrupt (time needed to switch from one process to another) takes 0.1 CPU seconds. The time needed to check the state of a process is 0.2 CPU seconds. Process 999 needs 5 CPU seconds to finish its instructions. Process 999 is either in the running or ready-to-run state. How much CPU time will be needed to finish running process 999?