"Employers hiring bank tellers are looking for candidates who can provide superb customer service regardless of stressful circumstances. Expect a lot of situational or role-play questions that will assess your ability to diffuse unsatisfied customers and handle money professionally. In addition, bank tellers must also be comfortable with counting and handling bills efficiently and accurately, so come prepared to answer a mental math counting teaser."
The very last question in the meeting was "How would you treat a customer?" and in the interview "What are your expectations for working here?"
There is no right answer. Just answer confidently because everyone is nervous and mumbling.