Are these languages regular or not? Yes$/$no plus the extra last two questions. Alphabet $\{$a$,$b$\}$ or

$\{0,1\}$f$.a^{{?}^{{?}^{?}}}n{b}^{{?}^{{?}^{?}}}m{a}^{{?}^{{?}^{?}}}k.n$ divisible by $3,m$&$k$ divisible by $5$

g$.w|$ first, middle and last symbols are the same

h$.ab$

i$.(ab{)}^{{?}^{{?}^{?}}}n(ab{)}^{{?}^{{?}^{?}}}n$

j$.$ strings that represent a binary number divisible by $3$