Hi could you please help with these problems? Thanks!

Note that in questions below na(w) and no(w) indicate the number of a's and the number of bs in string w. 1. Find a regular expression for the following languages over = {a,b}* (a) {w : w does not contain substring bbb} (b) {W : w contains exactly three a's and it ends with abb} (c) {w : na(w) mod 3 = 0 and w begins with ab} (d) {w : (na(w) + no(w)) mod 3 > 2} (e) {w : [w] mod 2 = 0} (f) L = {a"b" :mn > 4}