$3.$ For $\backslash$Sigma $=\{$a$,$ b$\},$ construct DFA$$s graph that accept the sets consisting of $($a$)$ all strings with exactly one a$.($b$)$ all strings with at least two a$$s$.($c$)$ all strings with no more than two a$$s$.($d$)$ all strings with at least one b and exactly two a$$s$.($e$)$ all the strings with exactly two a$$s and more than three b$$s$.$