Design DFA For the given language descriptions $($preferred with minimum states$).$

$1.$ A language the accepts words over alphabets $\{$a$,$b$\}$ containing even number a$$s and odd numbers of b$$s or odd numbers of a$$s and even numbers of b$$s$.$

$2.$ A language that accepts words over alphabets $\{$a$,$b$\}$ where number of a$$s in a word must be $3$n$+2$ with n$=0,1,2,....$

$3.$ For languages over $\{0,1\},$ strings representing binary numbers divisible by $7.$ Like $000,111,1110$ etc.