lexipixel - 2:53 am on Feb 1, 2012 (gmt 0)

"If I ask you if this path is safe, what will you answer?" "If ask you if this path is safe, will you say {}?" Almost anything will do, so long as it elicits a double negative -lucy24

No.

Using your question:

Question: If I ask you if this path is safe, what will you answer?

Path A / Guard A's answer: Yes. (truthful)

Path B / Guard B's answer: Yes. (liar)

How could you know from that?

You could not know the answer unless you ask each the specific question "Which path will the other guard say is safe?", and then choose the opposite path.