A process executes the following code

for (i = 0; i < n; i + +) fork ( ); 

The total number of child processes created is

Which of the following is/are true of the auto-increment addressing mode?
$${\rm I}.\,\,\,$$ It is useful in creating self-relocating code
$${\rm II}.\,\,\,$$ If it is included in an Instruction Set Architecture, then an additional $$ALU$$ is required for effective address calculation.
$${\rm III}.\,\,\,$$ The amount of increment depends on the size of the data item accessed

An operating system uses Shortest Remaining Time first $$(SRT)$$ process scheduling algorithm. Consider the arrival times and execution times for the following processes:

What is the total waiting time for process $$P2?$$

Consider three processes (process id $$0,1,2,$$ respectively) with compute time bursts $$2, 4,$$ and $$8$$ time units. All processes arrive at time zero. Consider the longest remaining time first $$(LRTF)$$ scheduling algorithm. In $$LRTF$$ ties are broken by giving priority to the process with the lowest process id. The average turn around time is