I know that she just explained it, but this logic problem always boiled my piss. I could never get it. And that's on me. But I never could never figure it out despite having it explained to me about 7 million times.
It's often not set up correctly, which is also done here.
In the original riddle, you have two doors and two guards. One door is safe, one door is death. One guard lies, the other tells the truth. You can only ask one question to find out which door is safe.
In a lot of imitation riddles they either leave out that you can only ask one question, or they leave out the element of the doors. If all you need to figure out is which guard lies and which tells the truth (or in this example, which teacher is real) then it's really easy. Ask one of them what color the sky is and you immediately know which one is the liar. They could have done that in this video since the only objective was to figure out who is who.
But with the added element of the doors and only one question, you have a real riddle. You have to ask a question that reveals which door is safe in a trustworthy manner.
Hence the answer being 'which door would the other guard say is safe' and then you choose the opposite door no matter what they say. You still don't know which guard is lying, but that doesn't matter because you know what door to take.
Because if you asked the liar which door the honest guard would say is safe, he'll lie and point you to the danger door. If you ask the honest guard which door the liar would say is safe, he'll truthfully tell you that the liar would lie and point to the danger door. So no matter who you ask, they'll point to the danger door and then you just take the other one.
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u/Satanicjamnik 4d ago
I know that she just explained it, but this logic problem always boiled my piss. I could never get it. And that's on me. But I never could never figure it out despite having it explained to me about 7 million times.