Who can see the questions or answers that I post?
When you ask a question, it is shared on your profile and in the News Feeds of your friends. If a friend answers or follows one of your questions, it will also create a story on their profile and within the News Feed of their friends, which increases the number of people who can view and answer your question. In this way, anyone on Facebook may participate in a question you ask so you can get answers from people outside your immediate friends.
You should only ask and answer questions that you are comfortable sharing with everyone on Facebook as the questions you have participated in are visible to everyone.
Note that when you ask a question in a group, only other group members can see and answer the question. Group questions will not be shared on your profile or in News Feed.