Answer by Subhash Trivedi:
The Intention here when asking questions is to see if the candidate has knowledge about the same, some times this questions are also meant to understand your psychology based on the answers you give.
Hence in case of knowledge based question you should, be honest and reply that I am not aware to this. (if you now some thing related to that question or question topic you can take a chance with interviewer permission and explain the thing.)
In case of question that would check your psychology you should just follow you instinct and say what feels best to you. (trust me you can not cheat on this questions)
Let me know if you need any more information on this.