The fork in the road
At a fork in the road between two cities, you see 2 people. One always tells the truth, and comes from the city of safety. The other person always lies and comes from the city of cannibals, where they will eat you. They both look exactly the same. You must choose one of the persons, and ask him one and only one question (no compound questions either, such as "is this shirt red and which way to safety?"). What question could you ask to find out which path leads to the city of safety?
posted by Foobar @ 10:39 AM
2 Comments:
Say the two roads are A and B.
Question should be "What will the other say if I ask him if A the road to safety?"
True person will say the truth, that means he'll say what the false person says, which is No it is not, if A is actually the road to safety.
False person will lie, that means he'll lie about what the true person will say which is No is it not.
=> A is the road to safety
Same thing can be obtained even if B was the road to safety.
Basically we are trying to get the FALSE binary result using one of the following 2 conditions:
1) TRUE AND FALSE
2) FALSE AND TRUE
In that case, Is this question considered as "compound question" ?
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