Brain Teasers

[Scott Huish]

Bill bets Craig $100 that he can predict the score of the hockey game before it starts. Craig agrees, but loses the bet. Why did Craig lose the bet?

 

[Oorang]

Because Bill was able to predict the score of the hockey game.

Alas Craig shouldn't be betting on tivo'd games.

 

[Scott Huish]

Um.. no

 

[Oorang]

Yoo hoo, Guard... Are you a liar?

That won't work, the lying guard is a liar and will lie, so he/she will say "No I am not a liar." The truth telling guard is not a liar and will tell the truth, so he/she will say "No I am not a liar." This doesn't tell you anything.

When you boil this problem down, the trick is to come up with a question that you know the answer to. Try this: "Pardon me, but are you a guard?"

http://en.wikipedia.org/wiki/Liar_paradox

 

[Oorang]

@HP. Did I make any statement that was contradicted by the question?

 

[Scott Huish]

Yes. If the game was Tivo'd, the game would've already been played and therefore started.

 

[PaddyD]

re the guards, ask either guard which door the other would suggest you walk through, then pick the other one.

 

[Oorang]

@PaddyD That's more in the spirit of the question (and I think the "Classical" answer). The funny thing is, the question lets you live but you never know who's lying. My way tells you whose lying, but you still have to take your chances with the doors (only 1 question). So I have to admit, my answer is inferior. *sigh*

@HP I was just joking about the Tivo bit. But the way the question is phrased it sounds like a literal answer is what you were looking for. Are you actually asking, "How was Bill able to make the prediction?"

 

[schielrn]

Bill bets Craig $100 that he can predict the score of the hockey game before it starts. Craig agrees, but loses the bet. Why did Craig lose the bet?

Bill predicts 0 to 0, because the score of the hockey game is 0 to 0 before it starts.

 

[PaddyD]

"Bill predicts 0 to 0, because the score of the hockey game is 0 to 0 before it starts"

If this is the 'right' answer, then I object on existential grounds Before the game starts, there is no score. 0:0 is, as it were, the positive absence of any goals during the game.