The Tenth Question: All or Nothing!

is episode 25 of the original Naruto anime.

Synopsis
The camera moves around and comes to class where the Genin are writing the exam. Ibiki Morino says that incompetent ones have already dropped, so he, after 45 minutes, can give the final, tenth question. But he says that there is one special rule for this question. In meanwhile, the scene moves to place where are Kakashi Hatake, Asuma Sarutobi and Kurenai Yuhi. Kakashi and Asuma explain to Kurenai that Ibiki is a great ninja, specialized for torture and interrogation.

Back in class, Ibiki says that they can chose whether or not they want to try solve tenth question. If they don't want to, the entire team will fail, but if they chose to answer the question and they don't know the answer, they will lose the privilege to take the Chunin Exams forever. Many of them have chose not to answer question and they leave the class. Naruto, in his loud style says: I'm not scared! I will take this exam! After that, Ibiki says that all who remain in the classroom (78 students) have pass. He then explains that the meaning of first nine questions were to see their information gathering skills, and the tenth question was the take or not take question. After that, through the window crashes second examiner, Anko Mitarashi. At the end of episode, Ibiki takes the one exam and smiles, because this was the first time he sees one student pass with empty exam.