Brain Teaser.... very hard

You and a partner may devise a stratagy before hand...

Take a single suit (the 13 spades for example) from a regular deck of cards.... get somebody to choose 5 cards and hand you the remaining 8 cards.... now you choose 5 cards and hand the remaining 3 cards to your partner. Your partner may only look at these 3 cards and must tell what cards each of you have choosen... no communication allowed except for the 3 cards.

Can you figure out a way to do this?

Comments

  • i'd be insanely impressed if someone solves this, i dont see how it's possible. i havent thought that hard about it though.

    Unless of course the cards are in some prearranged order, then it would be easy.
  • You and a partner may devise a stratagy before hand...

    If you've devised a strategy with your partner beforehand then I guess it's a matter of signaling the cards in your hand, and your partner will know the value of the other 5 cards by process of elimination.  That almost sounds too easy......... I must have missed something.
  • You and a partner may devise a stratagy before hand...

    If you've devised a strategy with your partner beforehand then I guess it's a matter of signaling the cards in your hand, and your partner will know the value of the other 5 cards by process of elimination.  That almost sounds too easy......... I must have missed something.

    but you cant look at any of the cards, as far as i could tell, only the 3 cards are seen? that doesnt seem right either though, i'm confused.
  • Yep, I just read the puzzle once again....... only the person holding 3 cards can look. Hmmm.....well if no one EVER gets to look, then you just make up any 5 cards. What do I win??
  • Yep, I just read the puzzle once again....... only the person holding 3 cards can look.  Hmmm.....well if no one EVER gets to look, then you  just make up any 5 cards.  What do I win??

    Yes it reminds me of this...

    http://www.snopes2.com/humor/info/card1.htm
  • literation wrote:

    freakin amazin...the first time you try it...  :fish:
  • I have to admit, I didn't get it until the second time through. Very clever indeed.
  • ok... to clarify a little, if you need it....

    George hands hank the 13 spades.... hank picks out 5... let's say the ace, 4, 5, jack & king....
    Hank hands the remaining cards back to George.... George takes x, y & Z and gives them to Scotty

    Scotty looks at x, y & Z and proceeds to tell Hank that he has the ace, 4, 5, jack, & king....

    Hank is impressed!!!

    No comunication takes place between George and Scotty except through the passing of the 3 cards... they could even be mailed to Scotty... How do they do it??
  • 13 spades are prearranged before hand? Thus theres probably some sort of complicated subset math involved in which you can figure out the other cards from only knowing 3.

    Or get superman with his xray vision.
  • To do that George would tell Scotty that he will not take certain cards out of the stack. Say for example he told scotty that he would not take the 3 lowest cards still available, in this case the 2,3,6. This would tell Scotty that the A, 4, and 5 have been removed. They could then have the 2 , 3 , 6 arranged in an order that would tell Scotty what the remaining cards are, say the 2, backwards 6 and backwards 3.

    This is just a guess but without coming up with a proof, it sounds very possible.
  • yeah, brain teasers that require mathetmatical proofs suck
  • Oh Oh, I feel a confrontation with BBC Z coming on. LOL
  • :rage:

    Flamers suck lol
  • From my puzzled math this seems doable (although I'm not sure how you figure it out "on the fly").

    By my math there are 10c5 = 252 possible combinations the 2 players hold (since you already can see the other 3 cards). Now from the 3 cards, he can draw this from 8 remaining plus if you factor in the order they are laid out, you would have 8c3 * 3! permutations = 336 possible combinations that you could represent with the 3 cards. As for the mappings, I'm still lost on that... Likely some crazy convolutional coding scheme or something...

    Hints?
  • From my puzzled math this seems doable (although I'm not sure how you figure it out "on the fly").

    By my math there are 10c5 = 252 possible combinations the 2 players hold (since you already can see the other 3 cards). Now from the 3 cards, he can draw this from 8 remaining plus if you factor in the order they are laid out, you would have 8c3 * 3! permutations = 336 possible combinations that you could represent with the 3 cards. As for the mappings, I'm still lost on that... Likely some crazy convolutional coding scheme or something...

    Hints?
    Finally some thoughtful insight...

    ok hints...
    ...the order you pass them makes a difference.
    ...in order to choose which 3 cards to pass, start with the lowest card that is 1 higher than a card you don't have but 1 lower than one you do! (was that confusing enough?)
  • I understood both the math and the solution as you propose it makes sense to me. I am having a few brain farts on this though.

    For those reading this who have yet not figured it out, Selecting the cards is the second hint. The idea is to pass the cards that indicate what you have and don't. Let's say there is the 2 3 5 and 6 left in the deck as the low cards. Mickey is suggesting that you pass the 2, indicating that the ace is already gone and that you have the 3. You could also pass the 5 for the same reason, the 4 is gone and you keep the 6.

    My issue is the situation where there is a large block of consecutive numbers out there. 1 2 3 4 5 6 7 8 9 is a possibility and that hint you gave is not so applicable in that case. In almost any other case I agree that there will be gaps and that the strategy would work.

    I am just complaining because that was a nice hint (as I said, I was leaning toward something like that in the first place) but not enough of one.
  • Now from the 3 cards, he can draw this from 8 remaining plus if you factor in the order they are laid out, you would have 8c3 * 3! permutations = 336 possible combinations that you could represent with the 3 cards.

    While it is true that you can see the 336 distinct pieces of information associated with these permutations, the fact that your partner does not know the 8 cards you're chosing from1 means that you may not actually be able to exchange information with your partner from the corresponding set of 336 distinct points.
    ...in order to choose which 3 cards to pass, start with the lowest card that is 1 higher than a card you don't have but 1 lower than one you do!

    Such a card may not exist. Counting the Ace as low (say), your adversary may pass you A2345678 or A234567K.

    This is not to say that the hint is not useful--- just that you need to deal with the special cases within whatever solution this hint is supposed to lead you to.
    ...the order you pass them makes a difference.

    I think that allowing the cards to be passed in a certain order is not really a hint. It must be a part of the original problem. That is to say that the "no other forms of communication" restriction must be clearly nailed down. It's reasonable to interpret the order in which the cards are passed to be "other communication".

    I had "solved" the original problem using numerous systems, all of which I'm sure were not intended to be solutions. I thought of encoding information by passing cards to my opponent in a ceratain order (which is apparently okay), with some cards face up and some face down, some cards turned at a 90 degree angle, some cards with my left hand, some cards passed with a 1 minute delay, etc, etc. The trouble is that while all of these certainly constitute passing cards to someone, all of these could also be interpreted as other forms of communication.

    And quite frankly, I'm dissapointed in this topic being posted on the forum in the first place, and by such a long time forum member. Remember to try to keep this forum ON TOPIC by sticking to only bad beat stories and/or "online poker is rigged" subject matter.2 Discussion of topics even remotely related to actual poker is grounds for a swift banning.

    ScottyZ

    1If your partner already knows the 8 cards you are choosing 3 from, you can pass him 3 random cards and win.

    2It's an exciting literary challenge to attempt to combine these two seemingly disparate topics.
  • ...in order to choose which 3 cards to pass, start with the lowest card that is 1 higher than a card you don't have but 1 lower than one you do!
    Such a card may not exist. Counting the Ace as low (say), your adversary may pass you A2345678 or A234567K.

    In general, most "coding" systems inherently assume a circular reference system.... eg. A23456789TJQKA2345678.... allowing for the fact that if your adversary pass you A2345678, your first choice for a card would be..... wait for it.... patience.... patience... the A.
  • ...in order to choose which 3 cards to pass, start with the lowest card that is 1 higher than a card you don't have but 1 lower than one you do!
    Such a card may not exist. Counting the Ace as low (say), your adversary may pass you A2345678 or A234567K.

    In general, most "coding" systems inherently assume a circular reference system.... eg. A23456789TJQKA2345678.... allowing for the fact that if your adversary pass you A2345678, your first choice for a card would be..... wait for it.... patience.... patience... the A.

    I thought that a circular order might have been what you meant, but then I was thrown off by the fact that you were using a word ("lowest") which does not apply to circular orderings.

    I think I still get what you mean though. Choose the lowest card in the usual ordering which satisfies the one above/one below condition in the circular ordering.

    ScottyZ
  • This whole deal sounds way too complex for me. I did notice though that nobody has thought of using the card passing idea with whether the cards are right side up or up side down. Using spades the A,3,5,6,7,9 all have a top and bottom. Maybe this wasn't the intent of the question but it could be used for information purposes.

    Paul
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