The Liar And The Trusted
Riddle: There were 2 doors, one was stuffed with treasure meanwhile the other had a pit to nowhere. Behind each door was a guard, one guard always told the truth while the other guard always told a lie. However you do not know which guard was on which door. You could only ask one question to any of the guards to figure out which one has the treasure. What might you ask to find out where the treasure is?
Answer: Go up to one of the guards and ask this question, " Hello, which door that your brother will point if I ask him which way is the heaven." Then take the other door. Don't enter the door that he was pointing. This question will work for both of them because if you ask this question to the truth guy, he will point the hell because he knows that the other guard will point hell and if you asked to the liar, he'll still point hell because he knows that the other guard will point to heaven door, so he lied. That's why you take the other door.
Source: https://www.riddles.com/3243
