L$1=$ the set of all strings that start with a or have odd length

b$)$ L$2=$ the set of all strings that start with b and have even length

c$)$ L$3=$ the set of all strings that end with a and have even length

d$)$ L$1\backslash$cap L$2$

e$)$ L$2$L$3$

f$)$ L$2\backslash$cap L$3$

g$)$ The set of all strings such that every occurrence of a is followed by at least three bs$,$ e$.$g$.,$ bbabbbb,

abbb, b$,$ babbbbabbbabbbbbbabbbbbbb are in this language, but babb, a$,$ bab are not.

h$)$ The set of all strings that does not contain pattern baba.

i$)$ The set of all strings except bab and ab$.$

j$)$ The set of all strings such that every even position $($position with even index$)$ contains a$.$ For example,

bab, bab, aaaaa, bababa are in this language, but abb and bbba are not. Note, that index of first

character in the string is equal to $1$