Consider a System with a two-level paging scheme in which a regular memory access takes $$150$$ nanoseconds, and servicing a page fault takes $$8$$ milliseconds. An average instruction takes $$100$$ nanoseconds of $$CPU$$ time, and two memory accesses. The $$TLB$$ hit ratio is $$90$$% and the page fault rate is one in every $$10,000$$ instructions. What is the effective average instruction execution time?

Consider an operating system capable of loading and executing a single sequential user process at a time. The disk head scheduling algorithm used is First Come First Served $$(FCFS).$$ If $$FCFS$$ is replaced by Shortest Seek Time First $$(SSTF),$$ claimed by the vendor to give $$50\% $$ better benchmark results, what is the expected improvement in the $${\rm I}/O$$ performance of user programs?

The goal of structured programming is to

Choose the best matching between the programming style in Group 1 and their characteristics in Group 2

Group 1
P. Functional
Q. Logic
R. Object-oriented
S. Imperative

Group 2
1. Command-based, procedural
2. Imperative, abstract data types
3. Side-effect free, declaretive, expression Evaluation
4. Declaretive, clausal representation, theorem proving