$($a$)$ Define the set A $=\{$r$,$ o$,$ t$,$ p$,$ c$\}$ and B $=\{$discrete$,$ math, position, computer, science$\}.$ Define the

relation R $$ A $$ B such that $($letter$,$ word$)$ is in the relation if that letter doesn't occur somewhere in

the word. Be careful $-$ recheck your answer again to see if you by mistake reversed the definition for

any pair $($if you mistakenly used $$does occur$$ for $$doesn$$t occur$).$ Even if you know the answer

psychological distraction can play a role. It can happen to me too!