Question

THINKING TIME! =) You are in a hallway. There are two doors. Each door has a guard who is the only person allowed to open that door. When one door is opened, you are sucked into a wormhole forever. When the other door is opened, you are sucked into a place that is gorgeous and peaceful. You know for a fact that one of the guards always lies. You also know for a fact that one of the guards always tells the truth. You don't know which guard is which. Once one door opens, you are sucked into that door's world. You are allowed to ask ONE QUESTION and you must ask that ONE QUESTION (exactly the same) to each guard. So... WHAT IS THE ONE QUESTION THAT YOU CAN ASK (EACH GUARD) TO KNOW FOR SURE WHICH DOOR LEADS TO THE PARADISE?

Answer 1

Answer:

I'm not taking credit for this answer but here's what I found on the web:

Explanation:

You ask one of them 'If I asked the other guard which one the  road to heaven was, which one would he say?'  

Then you take the OTHER road to the answer they give.

If you happened to have asked the 'Truth teller'; he knows that the liar would give the wrong road, and so he would answer the wrong road to your question.  

If you asked the 'Liar'; he would know that the 'Truth teller' would answer that it is the right road, and so as he is a liar, he would tell you the wrong road.  

Both people would give you the wrong road and so you pick the road which is not in their answer.

SOURCE: https://answers.yahoo.com/question/index?qid=20090421050313AA9gawh