Minimal Final States in DFA

Question

Ques:- What are the number of final states in minimal DFA, where ∑= {a, b}, if every string starts with “aa” and length of the string is not congruent to 0 (mod 4).

Comments

yes you are correct 3 is the correct

---

How is it 3 states I am getting total of 7 states of which  4 final states, 2 non final and 1 trap state?(correct me if I am wrong)

---

I got clarified I made 2nd state (after accepting 1 a ) as final state which is wrong

Answer 1

see this dfa. let me know if i'm wrong

Comments

1. Write transition table for congruent mod4

2. Apply complementation and then minimization