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DoctorHelvetica
United States15034 Posts
![[image loading]](http://i35.tinypic.com/24mx114.jpg) Try to come up with a solution to this puzzle, it took me a really long time to figure out. It's a good one. Solution: + Show Spoiler + C knows his hat is black, if his hat was white then D would have seen two white hats and yelled that his hat was black. Because D did not do this, C realized that D must be seeing 2 different hats and that his hat is therefore black.  | ||
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writer22816
United States5775 Posts
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madnessman
United States1581 Posts
EDIT: I GOT IT! + Show Spoiler + If B and Cs hats are the same color D knows that his hat is obviously the other color and can call it out. If D does not call out a color C knows his hat is a different color than the guy in front of him and can call it out. Here is another "guess the hat" brain teaser. This time there are 10 guys buried in the ground in a line. They are all facing forward so guy #1 can see everybody's hat (but his), guy #2 can see 3-10, guy #3 can see 4-10, etc... They each have a 50/50 chance of getting either a black or white hat (so it's not necessarily 5 x black and 5 x white). They all have to guess the color of their hat. Guy #1 guesses first, guy #2 guesses second, etc... They have time before the test to agree on a strategy. There is a strategy which will save at least 9/10 guys for sure. What is it? This isn't a trick question. They can't give audio clues like making your guess in a high pitch or a low pitch to tell the person in front of them what hat color they have. It's a logic/math solution. | ||
Flicky
England2663 Posts
To those working it out, this is completely logical. There is no trickery at all. I know the picture says it, but it's easy to doubt that. There's nothing like "he leans forward and the hat falls off". | ||
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HwangjaeTerran
Finland5967 Posts
no way they could´ve chosen a guy with white hat to be alone on the other side of the wall. | ||
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Ganfei
Taiwan1439 Posts
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underscore
252 Posts
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LordWeird
United States3411 Posts
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Phrogs!
Japan521 Posts
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Zinbiel
Sweden878 Posts
On October 31 2009 21:11 madnessman wrote: damn i'm really tempted to look at the solution. i've been staring at the diagram and instructions for like 5 minutes and i haven't figured it out yet. EDIT: I GOT IT! + Show Spoiler + If B and Cs hats are the same color D knows that his hat is obviously the other color and can call it out. If D does not call out a color C knows his hat is a different color than the guy in front of him and can call it out. Here is another "guess the hat" brain teaser. This time there are 10 guys buried in the ground in a line. They are all facing forward so guy #1 can see everybody's hat (but his), guy #2 can see 3-10, guy #3 can see 4-10, etc... They each have a 50/50 chance of getting either a black or white hat (so it's not necessarily 5 x black and 5 x white). They all have to guess the color of their hat. Guy #1 guesses first, guy #2 guesses second, etc... They have time before the test to agree on a strategy. There is a strategy which will save at least 9/10 guys for sure. What is it? This isn't a trick question. They can't give audio clues like making your guess in a high pitch or a low pitch to tell the person in front of them what hat color they have. It's a logic/math solution. This works, right? + Show Spoiler + If they agree that number 1 will guess white if he sees an odd number of white hats and guess black if he sees an even number of white hats. If number 1 calls white and number 2 sees an even number of white hats he's got a white one. If he sees an odd number he's got a black one. Rinse and repeat, everyone have to remember when it's there turn if they should have an even or odd number of whites in front of them. | ||
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Thats_The_Spirit
Netherlands138 Posts
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Adeny
Norway1233 Posts
Just because D sees 2 different colors doesn't mean that D's hat has to be white. For all he knows, A and C has white, B and D has black. Unfortunately your hat-men are left with a 50-50 guess for whomever is feeling lucky that day. | ||
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JeeJee
Canada5652 Posts
+ Show Spoiler + well C can see a white hat and i assume he knows that D can see both his and B's hats. therefore C knows that D sees a white + X. if D sees white+white, he'd auto-yell black. he doesn't, because he sees white+black. C realizes this and since he's not the white (cos he can see the white) he's sure he's black also @adeny + Show Spoiler + what? D's color doesn't matter, he's not the one guessing, because like you said, he can't be sure of his color cos he sees diff ones. C is the one guessing and C knows his color 100% given 2 conditions: -he knows that D can see B and C's hats -D is not an idiot | ||
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Zinbiel
Sweden878 Posts
On November 01 2009 01:09 Adeny wrote: There's actually no correct answer to OP's puzzle, not even his own answer. + Show Spoiler + Just because D sees 2 different colors doesn't mean that D's hat has to be white. For all he knows, A and C has white, B and D has black. Unfortunately your hat-men are left with a 50-50 guess for whomever is feeling lucky that day. You don't seem to understand. + Show Spoiler + Your scenario doesn't matter, since it isn't D who are the one with the information he needs to tell what color his hat is, it is C. C sees that B has a white hat. The fact that D doesnt cry out tells C that he and B has different colors and since he sees that B has a white one, hence his hat is black. If he had seen a black hat in front of him and no reaction from D, he would have a white hat. | ||
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kerpal
United Kingdom2695 Posts
On October 31 2009 21:22 NoobsOfWrath wrote: There are a lot of variations of this puzzle, I did a similar one back in one of my logic classes during freshman year of college. The part that irks me is that your answer relies on your compatriots (the other hat wearers) not being idiots. So that's kind of out of the question in a normal situation. puzzle should say, "this diagram shows 4 puzzle nerds buried up to their necks in sand" | ||
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-orb-
United States5770 Posts
it relies on D not being a retard. If I was C in that situation I would be scared as fuck to say my hat was black because I'd be worried D was just a dumbfuck tool and he didn't know what he was doing lol | ||
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ejac
United States1195 Posts
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Pengu1n
United States552 Posts
On November 01 2009 01:51 -orb- wrote: I don't like this one because + Show Spoiler + it relies on D not being a retard. If I was C in that situation I would be scared as fuck to say my hat was black because I'd be worried D was just a dumbfuck tool and he didn't know what he was doing lol This is why its just a fun logic puzzle. If it were a real live situation I think even the smartest people when trapped up to their necks so they can't move and are about to be executed would panic and lose most of their logical reasoning. Doesn't necessarily make them "dumbfuck retarded tools". However if this was a real life situation where there was no penalty or execution, just a 10 min time limit and people buried in the sand with hats just to try to figure out the riddle, then maybe it would be fair to call them dumb ;p | ||
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revolover
Canada134 Posts
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Dr.Lettuce
United Kingdom663 Posts
I think the answer is C. Because he knows B's hat is white. D would then have called out his hat was black, if C was white as well. However he didn't call out. Meaning he can see one white and black hat. Since B's is white. C can be 100% certain his hat is black? haha yes! that was damn satisfying | ||
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