回复：请教： job interview questions

I would say: "sorry, not sure this one...". If you try to answer but the answer is totally wrong, they may feel you are not honest...it makes the thing worse... The interviewer don't expect you know everything. Their feeling about you is more important.

If you remember the question, do a research after the interview and expalin it in the thank you letter. This will for sure give them positive impression.