Heaven and hell - rFronteddu/general_wiki GitHub Wiki

• There are two gates, one to hell and the other to heaven.
• Two gatekeepers, one for each gate.
• One of them always speaks the truth and the other always lies but you don’t know which one guards which gate.

You are allowed only one question and you need to find out the gate to heaven. What is the question?

Solution

“If I were to ask the other gatekeeper which gate leads to heaven, what would they say?”

Here’s how it works:

• If you ask the truthful gatekeeper, he will say hell, because the liar would point to hell.
• If you ask the liar gatekeeper, he will say hell too, because the truthful would point towards heaven and he has to lie.