After a long journey, you finally arrive at the edge o a deep gorge where there are two identical bridges from which to choose your path to the other side.
One bridge is safe, while the other is very dangerous and has caused the deaths of hundreds of travelers. The owner of the first bridge is a talking rat, while the owner of the second bridge is a talking frog. Friends told you before you left that one of the bridge owners always tells the truth, while the other always lies.
You are allowed one question to ask of either the frog or the rat to find out which bridge is the safe bridge. What is the question that you would ask?
Ask the frog the following question: "If I were to ask the rat which bridge is the same bridge, which one would he point to?"
If the frog is the truth teller, he would tell you that the rat would point to the dangerous bridge.
If the frog is the liar, the truth telling rat would point out the safe bridge, but the lying frog would tell you he said the dangerous bridge.
In both situations, the dangerous bridge would be pointed to. Take the other bridge.
One bridge is safe, while the other is very dangerous and has caused the deaths of hundreds of travelers. The owner of the first bridge is a talking rat, while the owner of the second bridge is a talking frog. Friends told you before you left that one of the bridge owners always tells the truth, while the other always lies.
You are allowed one question to ask of either the frog or the rat to find out which bridge is the safe bridge. What is the question that you would ask?
Ask the frog the following question: "If I were to ask the rat which bridge is the same bridge, which one would he point to?"
If the frog is the truth teller, he would tell you that the rat would point to the dangerous bridge.
If the frog is the liar, the truth telling rat would point out the safe bridge, but the lying frog would tell you he said the dangerous bridge.
In both situations, the dangerous bridge would be pointed to. Take the other bridge.