Brain Teaser #9 | FerrariChat
Buy

Brain Teaser #9

Discussion in 'Other Off Topic Forum' started by PeterS, Jul 6, 2004.

This site may earn a commission from merchant affiliate links, including eBay, Amazon, Skimlinks, and others.

  1. PeterS

    PeterS Five Time F1 World Champ
    Silver Subscribed

    Jan 24, 2003
    52,065
    Goodyear, AZ
    Full Name:
    PeterS
    #1 PeterS, Jul 6, 2004
    Last edited by a moderator: Sep 7, 2017
    Shown are 4 men buried up to their necks in the ground. They can not move so can only look forward. Between A and B is a brick wall which can not be seen through. They know that between them are 4 hats, 2 are black and 2 are white, but they do not know which color they are wearing. In order to avoid being shot, one of them must call out to the executioner the color of their hat. If they get it wrong, everyone will be shot. They are not allowed to talk to each other.

    Question: Which one of them calls out ?
    Image Unavailable, Please Login
     
  2. coolestkidever

    coolestkidever F1 Veteran

    Feb 28, 2004
    5,538
    NJ
    Full Name:
    Patrick
    #2 coolestkidever, Jul 6, 2004
    The logical answer would be D b/c he can see the most hats. But i have a feeling that isnt correct. So i would choose A because he has a 50/50 chance of choosing the right color, the others have less of a chance b/c they can see more hats and their thought process is different. I really dont know so im guessing
     
  3. 134282

    134282 Four Time F1 World Champ
    BANNED

    Aug 3, 2002
    40,647
    California
    Full Name:
    Carbon McCoy
    #3 134282, Jul 6, 2004
    i put on my robe and wizard hat...
     
  4. Auraraptor

    Auraraptor F1 World Champ
    Lifetime Rossa Owner

    Sep 25, 2002
    13,958
    MO
    Full Name:
    Omar
    #4 Auraraptor, Jul 6, 2004
    If D sees 2 of the same color, he can call the opp. color, saving them all.
     
  5. matterhorn762

    matterhorn762 Formula Junior

    Apr 19, 2004
    340
    Tennessee
    #5 matterhorn762, Jul 6, 2004
    The odds of each person being correct is in my opinon:

    A: 50%
    B: 50%
    C: 67%
    D: 75%

    D has a 75% chance of being correct because he will know for sure the color of B and C, and half the time they will be the same color. The other half of the time he can guess with a 50% chance, so a total of 75% odds.

    I don't see a way for anybody to be 100% sure?
     
  6. fivebob

    fivebob Formula Junior

    Jan 31, 2004
    254
    Tauranga,New Zealand
    Full Name:
    Callum
    #6 fivebob, Jul 6, 2004
    C, he knows that because D did not say anything that he(C) has a different hat from B. He can see B's hat and therefore knows the colour of his hat.
     
  7. PeterS

    PeterS Five Time F1 World Champ
    Silver Subscribed

    Jan 24, 2003
    52,065
    Goodyear, AZ
    Full Name:
    PeterS
    #7 PeterS, Jul 6, 2004
    "I don't see a way for anybody to be 100% sure?"........There is....and nobody has got it yet.
     
  8. matterhorn762

    matterhorn762 Formula Junior

    Apr 19, 2004
    340
    Tennessee
    #8 matterhorn762, Jul 6, 2004
    And nobody is allowed to say a word, right? I'll think about it some more then.
     
  9. PeterS

    PeterS Five Time F1 World Champ
    Silver Subscribed

    Jan 24, 2003
    52,065
    Goodyear, AZ
    Full Name:
    PeterS
    #9 PeterS, Jul 6, 2004
    I guess anyone can say anything they want! This damn puzzle took me a while to figure out (and it pi$$ed me off!).
     
  10. Miltonian

    Miltonian F1 Veteran

    Dec 11, 2002
    5,966
    Milton, Wash.
    Full Name:
    Jeff B.
    #10 Miltonian, Jul 6, 2004
    D does not call out, because B & C are different, and therefore D does not know the answer.

    C realizes that he and B must be different, because D did not call out.

    C sees that B is white, so he knows that he must be black.

    C calls out, "my hat is black!"
     
  11. matterhorn762

    matterhorn762 Formula Junior

    Apr 19, 2004
    340
    Tennessee
    #11 matterhorn762, Jul 6, 2004
    Then it's simple. If B and C are the same colored hat, then D knows what he is and says that he is the opposite color.

    If B and C are different colored hats, D doesn't say anything and B and C know that they have different colored hats from each other. C therefore looks at whatever B has, and says the opposite.

    No talking involved actually, though it's assuming they're down with the plan!
     
  12. coolestkidever

    coolestkidever F1 Veteran

    Feb 28, 2004
    5,538
    NJ
    Full Name:
    Patrick
    #12 coolestkidever, Jul 6, 2004
    I over thought this way to much. That was so simple. damn
     
  13. PeterS

    PeterS Five Time F1 World Champ
    Silver Subscribed

    Jan 24, 2003
    52,065
    Goodyear, AZ
    Full Name:
    PeterS
    #13 PeterS, Jul 6, 2004
    Bingo!

    After a while, C comes to the realization that he must answer. This is because D can't answer, and neither can A or B. D can see C and B, but can't determine his own hat color. B can't see anyone and also can't determine his own hat color. A is in the same situation as B, where he can't see anyone and can't determine his own hat color. Since A, B, and D are silent, that leaves C. C knows he is wearing a black hat because if D saw that both B and C were wearing white hats, then he would have answered. But since D is silent, C knows that he must be wearing a black hat as B (who he can see) is wearing a white hat.
     
  14. fivebob

    fivebob Formula Junior

    Jan 31, 2004
    254
    Tauranga,New Zealand
    Full Name:
    Callum
    #14 fivebob, Jul 6, 2004
    Funny, that's what I said back in post #6, guess you must've missed that one ;)
     
  15. Forza1

    Forza1 Formula Junior

    Mar 20, 2004
    490
    California
    #15 Forza1, Jul 6, 2004

    For the merciful love of God, don't let them hit double digits!



    -DC
     
  16. PeterS

    PeterS Five Time F1 World Champ
    Silver Subscribed

    Jan 24, 2003
    52,065
    Goodyear, AZ
    Full Name:
    PeterS
    #16 PeterS, Jul 6, 2004
    Forza, How about taking this post and your last post on the 'Separate Threads' post and sticking it in your ear. It's summertime, it's hot and it's time to relax. You seem to be the only one that is really bugged by this. Just for that, I hope I get to 'Brain Teaser #666' just to pi$$ you off!
     
  17. darth550

    darth550 Six Time F1 World Champ
    Lifetime Rossa

    Jul 14, 2003
    61,113
    In front of you
    Full Name:
    BCHC
    #17 darth550, Jul 6, 2004
    Before being shot to death for not knowing the answer to this #$87^!)*o riddle...Beldar's called out for one last romp with the
    "Senso-ring" as his last request !

    DL
     
  18. Miltonian

    Miltonian F1 Veteran

    Dec 11, 2002
    5,966
    Milton, Wash.
    Full Name:
    Jeff B.
    #18 Miltonian, Jul 6, 2004
    Somehow, I didn't see that fivebob had the correct answer way before I did. Sorry, fivebob - you got it first!
     
  19. 62 250 GTO

    62 250 GTO F1 Veteran

    Jan 9, 2004
    7,765
    Nova Scotia Canada
    Full Name:
    Neil
    #19 62 250 GTO, Jul 7, 2004
    If this took place in Halifax, everyone would shout "my hat is black" "my hat is white". All at once and over and over. :(
     
  20. Bimmerista

    Bimmerista Formula 3

    Feb 7, 2004
    1,765
    Carrollton, TX
    Full Name:
    Mike
    #20 Bimmerista, Jul 7, 2004
    Ever wonder what if the pattern of the hat colours were different?? Lets say A & B were wearing black and C & D were wearing white.
     
  21. jimpo1

    jimpo1 Two Time F1 World Champ
    Owner Silver Subscribed

    Jul 30, 2001
    24,901
    Dallas, TX
    Full Name:
    Jim E
    #21 jimpo1, Jul 7, 2004
    C.

    Now I'll read everyone elses answer.
     

Share This Page