In a resident $$–OS$$ computer, which of the following systems must reside in the main memory under all situations?

The overlay tree for a program is as shown below:

What will be the size of the partition (in physical memory) required to load (and run) this program?

A counting semaphore was initialized to 10. Then 6 P (wait) operations and 4 V (signal) operations were completed on this semaphore. The resulting value of the semaphore

In a computer system where the ‘best-fit’ algorithm is used for allocating ‘jobs’ to ‘memory partitions’, the following situation was encountered:

When will the $$20$$ $$K$$ job complete?