Quiz / logic question

^^^^ What would you ask to ascertain which was the liar?

If I ask B a question, will he tell me the truth?

"Were I to ask the other fellow which one of you is a liar, what would he say?"

That didn't last long. WD!

Apologies, IAWN, it's very similar to something I'd heard before so I should have stayed quiet. Always tough to resist a quiz question. :)

It's normally couched as a biblical conundrum.

The question you want answered correctly is asked as "what would the other chap answer if ....?" . You then take the opposite .
EG
A traveller comes to a fork in the road and the only person he can ask for directions can be either liar or truthteller .
"What would a member of the other tribe say if I asked for the correct road?"
The answer is given and you take the opposite route.

It is a long time since I have come across this question.

Two positives or negatives become a positive but positive and negative is negative .

will germany win the world cup.....?

I liked the answer given by Kasper Hauser in the "The Enigma Of Kasper Hauser".

Kaspar: I should ask the man whether he was a tree-frog. The man from the truth village would say: “No, I’m not a tree-frog”, because he tells the truth. The man from the liars’ village would say: “Yes, I’m a tree-frog”, because he would tell a lie. So I know where he comes from.

hfink - for you!! - https://www.youtube.com/watch?v=C9uqPeIYMik


"Understanding is secondary, the reasoning is the thing"

Thanks blackburn, it's a great clip isn't. It's certainly hard do argue with Kasper's 'reasoning'!   I caught the film a few years back when Film4 were running a season of Herzog films and this scene was a real laugh out loud moment, so that's probably why it stuck in the mind. It's a marvellous film by a marvellous director.

*isn't it