Question

Which of the following is type 3 language ?

(a) Strings of 0’s whose length is perfect square

(b) Palindromes string

(c) Strings of 0’s having length prime number

(d) String of odd number of 0’s

The question was posed to me by my school teacher while I was bunking the class.

The doubt is from Union, Intersection & Complement in section Finite Automata of Automata Theory

Answer 1

Correct answer is (d) String of odd number of 0’s

The explanation: Only d is regular language.