Answer The Following Riddle, Can You Help?

You ask either guard, "If i ask the other guard the way out, what will he tell me?"  the lying guard will tell you the incorrect path, because he will lie about what the truthful guard would say.  the truthful guard will tell you the incorrect path also, becasue he is telling you truthfully what the lying guard will say.  either way, you know which way not to go.

Let guard A always tell truth and Guard B always tell lie.

So I would like to ask one question from both the guards and that is "What will your answer be if I ask you if your path leads out?"

If guard says Yes, then it’s a correct path and will lead you out. But if the guard says No, then it does not. Let me explain you this in detail.

If you ask this question from Guard A which tells the truth then he will answer it truly; "yes" if the path leads out and "no" if it doesn’t.

Now the problem is with B (who always lie). If you ask a question like if his path leads out, then he will simply answer “no”(false) if it does and “yes” (false) if it doesn’t. So in order to have the truth from him you have to ask the question from him which forces him to tell the truth like the one I motioned above "What will your answer be if I ask you if your path leads out?".  As you know that he would lie about what his answer would be. Thus started to lie about his lie and at the end give the true answer. He would answer right, with their 1st lie canceling out the 2nd lie. Giving the situation like

(B’)’ = B

So this is how both the guards will speak the truth.

This is a great riddle and I have seen it in different forms and situations and I can never remember the solution, so I had to look it up.  I should say one of the solutions, but I like this one.

Assume that the path to the right goes to safety outside.

Ask one of the guards, "If I had asked you yesterday how to get out of here safely, which path would you have told me to take"?

If you have asked the truthful one, he will say take that path there to the right.

If you have chosen the liar, he knows that yesterday he would have sent you to the bad path to the left (he always lies).  Now he has to answer your current question with a lie, so he has to tell you that yesterday he would have told you to take the path to the right.

Both say go right and one of them has to be the one that always tells the truth.

The lying guard with tell him the incorrect way so just go the opposite way of the answer the  lying guard give you