Last year I made a simple IRC question answering bot that just searched reddit for your question and returned the top comment of the top result. It worked surprisingly well. It's amazing how many questions someone else has asked on reddit before. And the comment quality is usually pretty good. Sample conversation with it: https://i.imgur.com/LDD9isL.jpg
I improved on it a lot with a whitelist of subreddits and some machine learning to select the best thread. But I was only touching on what is possible with that data.
You can play with it here: https://kiwiirc.com/client/irc.snoonet.org/mybots
EDIT: It does only work well with certain kinds of questions. Thing's that would have been asked before and without too many unique keywords. I see some people ask it really unique questions, or talk to it like a regular chatbot without even asking questions. And then get frustrated when it returns nonsense. There are a lot of improvements that could be made with this with natural language processing and stuff. But right now it's pretty simple.