Can one answer a question with a question?

No, it's not. We aim to grow simple questions and answers -- Q&A's that can become part of FAQs. We don't want WikiAnswers to be just another Web discussion forum. From experience we've found that allowing follow-up questions turns question pages into discussion threads.

Instead of asking a follow-up question, ask a new question.

I don't know, is it? Seriously though this can be proper in some situations such as a if a teacher uses this method to help a student derive their own answer and in turn grasp a greater understanding, in most cases though, such as on this site, it is not.