Question $2.$ Write the regular expression for the following languages $(3\mathrm{.}5$ marks$)$:

a$)$ For all palindrome strings on the alphabet $\{0,1\}(1$ mark$)$

b$)$ For all strings that have an even number of a$\text{'}$s on the alphabet $\{a,b\}(1$ mark$)$

c$)$ For all strings that start with $\text{'}a\text{'},$ end with $\text{'}b\text{'},$ and have an even number of a$\text{'}$s in total. $(1\mathrm{.}5$ mark$)$