c$.$ Construct r$.$e$.$ which denotes a language $L$ over the set $=\{0\}$ having even

length of string.

d$.$ Write r$.$e$.$ which denotes a language $L$ over the set $=\{1\}$ having odd length of

strings.

e$.$ Construct regular expression for the language $L$ over the set $=\{a,b\}$ in which

the total number of a$\text{'}$s are divisible by $3.$