You come to a fork in the road and you need to get to the castle. There are 2 people there who know which road to take. One always tells the truth and one always lies. Problem is that you don’t know who is the truth-teller and who is the liar. You get to ask only one question to one of them. What question can you ask that will get you to the castle?
Hidden:
If I’d ask the other one which road to take what would he answer?
To be fair I remember this riddle or a similar version of it from years ago
You come to a fork in the road and you need to get to the castle. There are 2 people there who know which road to take. One always tells the truth and one always lies. Problem is that you don’t know who is the truth-teller and who is the liar. You get to ask only one question to one of them. What question can you ask that will get you to the castle?
4 people take a walk at night. They come to a dark tunnel. Only 2 people could cross the tunnel at the same time. They have a candle that burns exactly 13 minutes.
It takes Sara 6 minutes to walk across, Rivka 5 minutes to cross, Rochel 2 minutes, and Leah 1 minute. How do they all cross the tunnel with the candle?
Hidden:
Rochel and Leah go together, Leah comes back. 3 minutes
Sarah and Rivka go and rochel comes back 8 minutes
Rochel and Leah go. 2 minutes.
Equals 13
You come to a fork in the road and you need to get to the castle. There are 2 people there who know which road to take. One always tells the truth and one always lies. Problem is that you don’t know who is the truth-teller and who is the liar. You get to ask only one question to one of them. What question can you ask that will get you to the castle?
Hidden:
How abt you ask person A “will person B tell me to go right?”
•If A is truthteller and castle is on right he will say No
•If A is truthteller and castle is on left he will say Yes
•If A is liar and castle is on right he will say No
•If A is liar and castle is on left he will say Yes
So either way if the answer is No, that means it’s ok right and vice versa
How abt you ask person A “will person B tell me to go right?”
•If A is truthteller and castle is on right he will say No
•If A is truthteller and castle is on left he will say Yes
•If A is liar and castle is on right he will say No
•If A is liar and castle is on left he will say Yes
So either way if the answer is No, that means it’s ok right and vice versa
That should work. The simple answer is, ask one of them what the other one would tell you, and then go in the other direction.
Larry the Liar will lie, and tell you the opposite of what Truthful Tom would say, I.e. the wrong way. Truthful Tom would tell you what Liar Larry would say, I.e. the wrong way. So you go the other way.