"If X then Y unless Z" is represented by which of the following formulas in propositional logic? (" $$\neg $$ " is negation, " $$ \wedge $$ " is conjunction, and " $$ \to $$ " is implication)

Which of the following scheduling algorithms is non-preemptive?

Which of the following is not a form of memory?

The optimal page replacement algorithm will select the page that.