The interviewer wants to determine your boundaries. It is important to demonstrate you can manage anything that comes your way.

Always review the job posting before the interview and keep it closeby at the time of the interview. Provide example of easy and difficult duties on the job posting, and how easily you will be able to manage both. Provide example of the successful performance of these duties in a previous position where you had Typist duties (i.e., the position does not have to officially be "Typist"), if you have any.