an IQ question for all to solve.
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My goodness! Did you even read my previous post?Originally posted by dragg:thats why there is no logical answer.
I already said that C can deduce logically that he is wearing a red hat also from the fact that:
1) No one has left yet
2) Logical deduction -
c could be wearing green.Originally posted by DriftingGuy:My goodness! Did you read my previous post?
I already said that C can deduce logically that he is wearing a red hat also from the fact that:
1) No one has left yet
2) Logical deduction
how did he know the colour of his own hat? -
was parameter 1 stated in the question?Originally posted by DriftingGuy:My goodness! Did you even read my previous post?
I already said that C can deduce logically that he is wearing a red hat also from the fact that:
1) No one has left yet
2) Logical deduction -
i already gave the answer worOriginally posted by dragg:thats why there is no logical answer. -
Hisoka... can help me explain.. i really tired worOriginally posted by dragg:c could be wearing green.
how did he know the colour of his own hat?
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To tell you the truth.. i heard of this question before.. She never explain carefully.. that why so many people also sala.. parameter 1 by right should be in.. in fact its the quiz's solving keyOriginally posted by lost.sheep:was parameter 1 stated in the question? -
hey everyone! this is the correct answer! Fatum also has the correct answer. yeaps yeaps. i've discussed it with my boyfriend just now. AND IT IS LOGICAL. let me rephrase this answer...hopefully you all will understand. ^^Originally posted by DriftingGuy:Fatum already posted the correct answer.
The only scenarios for all three to raise hands are:
1) 2 red 1 green, everyone will see at LEAST one red hat
2) all three red hats
For scenario 1:
a) If I wear a green hat, someone will leave. Since, they deduce that either one of them two must be a red hat in order for all three hands to raise up.
b) If someone else wear green, but me and another guy wears red.. then i will immediately know that i am red hat in order for all three hands to raise up.
But neither me nor that someone else can immediately know and leave. Therefore from the hesitation, I can deduce that scenario 1 is impossible and scenario 2 is the answer: we all wearing red hats.
Guy C is smart, but if Guy B also can leave after Guy C then he is a genius. Since Guy B must also deduce what Guy C is thinking!!!
ok...
let's say A wears a green hat. all 3 hands are raised.
in B's view, he can see that A is wearing a green hat. therefore C is raising his hand due to B's red hat. therefore, B can deduce logically that C is raising his hand towards B's red hat. so B will leave the room.
C himself would also see that he is wearing a red hat (same viewpoint as B) and leave the room.
next scenario.
let's say C is wearing a green hat.
All hands are raised as well.
In A's view, he is raising his hand because he saw B's red hat. he also takes notice of C's green hat. A can then safely deduce that B is putting up his hand because of A's red hat.
In B's view, it would be the same as A's. they would then have already leave the room, having known for sure that both of them (A and B) are wearing red hats.
HOWEVER.
A and B did not leave the room. they may be hesitating because they do not know for whom is each raising their hands for.
therefore, C can safely deduce that C himself is wearing a red hat in order to cause such hesitation.
get it?? hehe. interesting right!
yay! next week i can hao lian to the teacher. hahaha. kidding. ^^ -
answer provided
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haha. very simple answer with not much details. but correct. ^^Originally posted by hisoka:because the other 2 didn't walk out so his must be red also because if his is green then on of the others could have got an answer -
i dont understand. in your question you already said all wear red hats. that mean a, b and c all have seen 2 red hats each.
so green hat does not come into the picture anymore. -
Yes, there are 3 red hats.Originally posted by dragg:i dont understand. in your question you already said all wear red hats. that mean a, b and c all have seen 2 red hats each.
so green hat does not come into the picture anymore.
Unfortunately, Guy C can only see 2 red hats, but he cannot confirm that he also wear red hat.
Why? Because if he wear green hat, all three still raise hands.
The criteria is, if you see anyone wear red hat, then raise hand.
So even if Guy C wear green hat, A and B will still raise hand. A raise hand cos he see B. B raise hand cos he see A. C see either A or B so he also raise hand.
Must remember that Guy C only know 3 things:
1) A and B wear red hats
2) They all raise hands
3) No one has left yet
So Guy C just from seeing the number of raised hands will still not know whether he wear red or green.
He must also think of what happens if he wear green or red. -
hi. i understand your frustration.Originally posted by dragg:i dont understand. in your question you already said all wear red hats. that mean a, b and c all have seen 2 red hats each.
so green hat does not come into the picture anymore.
indeed, all are wearing red hats. and green does not come into the picture at all.
in my above solution, i'm just writing out what C may be thinking in his mind.
put yourself into the shoes of C.
you don't know what hat you are wearing. but there are 2 possibilities, right? either green hat or red hat.
IF you are wearing a green hat, A and B would have already left the room, knowing for sure that they are wearing red hats. because:
1) A sees that B is wearing a red hat and C is wearing a green hat. All hands are put up. A will know definitely that B's hand is raised because of A's red hat. (makes sense to you? B can't be raising to C's green hat what.)
2) B would also see that A is wearing a red hat and C is wearing a green hat. same thinking as A. B would know that A is raising his hand to B's red hair, not C's green hat. makes sense?
therefore, just by thinking of this scenario (of when C is wearing a green hat), C would already have known he is NOT wearing a green hat because nobody has left the room.
therefore, C KNOWS he is wearing a red hat.
(NOTE: even if C is wearing a green hat, all hands will still be raised. makes sense? coz each one will at least see one red hat.)
hope this helps! read carefully and think again....if you still can't get it...hmm...just say what makes you blur again ba. -
never mind.
i shall wait for tues when you get the final answer. -
this IS the final answer. there is no other way...i'm very sure.Originally posted by dragg:never mind.
i shall wait for tues when you get the final answer. -
For everyone to raise their hands, the only combinations possible are either 2 red hats & 1 green hat OR 3 red hats.
Basically, since these are the only 2 possible combinations, anyone who sees a green hat can walk out knowing that his is a red hat.
If, however, they saw 2 red hats, it is always possible for theirs to be a green hat.
Since neither A & B saw a green hat, they did not walk out, as it was always possible that theirs could be green.
C sees them wondering, and he knows that his has to be red hat, for if his was a green hat, neither A or B would hesitate to move out.
edit: sorry post too slow...lol. i think mine is a simpler and clearer explanation though. -
it still funny. the question indicated a, b and c are all in red hats.
the fact is
c saw a and b in red hats
b saw a and c in red hats
a saw b and c in red hats. -
C does not know that A & B see 2 red hats.Originally posted by dragg:it still funny. the question indicated a, b and c are all in red hats.
the fact is
c saw a and b in red hats
b saw a and c in red hats
a saw b and c in red hats.
However, through logical thinking, he can deduce that his is red, because if his was green, both A & B would have walked out.
Since they hesistated to walk out, he knew that his must be red too. -
[quote]Originally posted by JennTS:
[b]
C does not know that A & B see 2 red hats.
However, through logical thinking, he can deduce that his is red, because if his was green, both A & B would have walked out.
why? -
Actually she(applesweetgirl) is trying to explain the ans in so call the 'opposite method' or wat ever u call it... wic means tat, instead of telling u the direct ans to y something can be done in tat particular way, she explains it by saying why tat thing cannot be done by other exsisting ways.
Example:
there are 3 paths, A, B and C, to the city named D
A to D is the shortest path.
instead of telling u A to D is the shortest path, i can also say B to D and C to D are longer paths...
So by bringing in the greens hats, the ans can be explained in this form.
Something like tat lah... if u all get wat i mean... -
Originally posted by Advent_Surge:
Actually she(applesweetgirl) is trying to explain the ans in so call the 'opposite method' or wat ever u call it... wic means tat, instead of telling u the direct ans to y something [b]can be done in tat particular way, she explains it by saying why tat thing cannot be done by other exsisting ways.
Example:
there are 3 paths, A, B and C, to the city named D
A to D is the shortest path.
instead of telling u A to D is the shortest path, i can also say B to D and C to D are longer paths...
So by bringing in the greens hats, the ans can be explained in this form.
Something like tat lah... if u all get wat i mean...
your explanation is really short.
but i dont understand.
[/b] -
another reason i could think of is, the guy who won, pay another guy kopi rui, then woohoo...he won!...
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thats okay...i dont understand it either...lol.Originally posted by dragg:your explanation is really short.
but i dont understand.
anyway, like i said in my previous post. its only possible to have a maximum of one green hat, since everyone rose their hands. because, if there were 2 green hats, one person would not raise their hand.
so, since its only possible to have one green hat, that would mean if A or B see someone else wearing a green hat, theirs definatly has to be red. since they know they are wearing a red hat, they would therefore walk out. -
I'm trying to say that, instead of telling u y things can be done tat way, i can also say y things cannot be done in other ways, so as to eliminated the wrong choices until the 1 correct method is left. in this case, it is good to use this method, because there are only 2 conditions, green or red. Pls continue reading to understand...
so, by saying IF C was the one wearing green hat, A and B will still rasie their hands, coz A saw B wearing red. and A saw C in green.
similarly B saw A wearing red, and saw C wearing green.
So, A will know B is raising his hands becoz of him(A), coz C is in green.
and B will know A is raising his hands becoz of him(B), coz C is in green.
So both of them (A and B) will walk out because they know their hats are red.
BUT BUT BUT BUT BUT, A and B didn't walk out! Which means C must not be wearing green! he is wearing red coz there is only 2 colors, either green or red!
i have tried to explain in my fullest capabilities...
well... is it better now??
thx for ur attention! -
A - red
B - red
C see them both red
none of them exit means they unsure of their color.
however all 3 hands are raised, meaning 3 reds or 2reds 1 green.
since 2 reds 1 green would mean both reds know they are red and thus leave the room.
but since none leave until C left, meaning 3 reds and they dont know they have 3 reds until C left.
once A know B is red
or B know A is red
both will know C is green and thus know they are red.
however since A know B and C is red
B know A C red
C know A B red
and none left means C got to be red or else the other 2 would have left. -
din totally go thru other posts....but issit:
A, B & C all think their own hat is green coz they all see 2 red hats.
A says his hat is green but he is wrong.
Again B says his hat is green & he is oso wrong.
C then thinks:
- A muz hav seen B & C's hat is red, so he thinks his own color is green.
- B oso sees A & C's hat is red, so he guesses his color is green.
but both A & B is wrong as C can see for himself they are both red hats.
A & B's answers tell C tat they both saw red hats.
overlapping both wat A & B sees, C is clearly wearing red so tat is how he derive his guess.
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all these assuming they all think there r 2 red & 1 green hats since they r told there r green & red hats. lets see....