Question: You are walking down a path until there is a fork in the road. One side is the good path and the on the other side is the bad path. However you don't know which one is which. Both paths have identical twins guarding the paths. One guard tells the truth, the other lies all the time no matter what. But still you don't know which one tells the truth or which one tell lies. If you want to to go to the good path, what question should you ask the guards
Answer: You would ask "which path would your brother go?" Take the opposite path they are pointing
Question: There were 2 doors. Behind the 1 door, is hell and behind the other door, is heaven but you don't know which door will take you to heaven. In front of them, there were 2 brothers, which is guarding the door. One of the brother always lie and the other one always tell the truth. Of course you don't know who is lying and who is not. You only get 1 question to ask one of them to figure out which door leads to heaven. What question you might ask? Remember you only get to ask 1 question. it means that you can't ask one question each of them. that will be 2 questions. You only ask 1 question to any of them and no more. How do you do that?
Answer: Go up to one of the guy 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 his brother will point hell and if you asked to the liar, he'll still point hell because he knows that his brother will point to heaven door, so he lied. That's why you take the other door.