If a minister takes a question on "notice" during question time how long do they have to answer and is it published?

Hi Paul, thanks for your question. You are right, sometimes a minister is asked a question in Question Time which they cannot answer. The question can then be ‘taken on notice’ and responded to later in writing. The minister will prepare an answer to the question and publish it in Hansard.  

There is no set time in which questions must be answered. However, if the question hasn’t been answered within 30 days (in the Senate) or 60 days (in the House of Representatives) the minister can be asked for an explanation.

Ministers can also be asked questions on notice. These are written questions to a minister from any member of Parliament. These questions are used to ask for detailed information. Questions on notice are included on the Notice Paper—the list of all business before the Senate and House of Representatives—and answers are published in Hansard.