However, working a lot of hours isn't necessarily a good thing - it could mean you're not productive enough to get the job done in a reasonable amount of time.
So, unless you're sure about the company culture and expectations, the safest answer is not to mention a certain number of hours. Rather, mention that you work as much as necessary to get the job done.
Your response will show the employer that you're willing to work hard, without committing to an exact number of hours per week.
More Job Interview Questions and Answers
Interview Questions and Answers
Typical job interview questions and sample answers.
Interview Questions to Ask
Questions for candidates for employment to ask the interviewer.