Red dot, blue dot

ricochet

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The Monty Hall problem post reminded me of another puzzle.

A man is shipwrecked on a remote island. The inhabitants of this island are born with either a red dot or a blue dot on their forehead and they never discuss the color of their dot. In fact, their religion states that if they figure out what color dot they have they must throw themselves in the volcano at dawn the next morning. The people also have perfect logic and deductive reasoning skills. After a few weeks the shipwrecked man builds a new boat and one day at noon he leaves. All the natives are present to see the stranger off, and just as he is leaving he says "At least one of you has a blue dot".

What happens?
 

everyyard

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The Monty Hall problem post reminded me of another puzzle.

A man is shipwrecked on a remote island. The inhabitants of this island are born with either a red dot or a blue dot on their forehead and they never discuss the color of their dot. In fact, their religion states that if they figure out what color dot they have they must throw themselves in the volcano at dawn the next morning. The people also have perfect logic and deductive reasoning skills. After a few weeks the shipwrecked man builds a new boat and one day at noon he leaves. All the natives are present to see the stranger off, and just as he is leaving he says "At least one of you has a blue dot".

What happens?

probably they all jump in the volcano because they are all red dots and by saying this, they look around see only red dots and assume they must be the blue dot.
 

Clonehomer

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Apr 11, 2006
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Depends. If more than one person has a blue dot then nothing because they still can't figure out how many have a blue dot. If it is only one person then the person with the blue dot will figure it out and kill himself setting off a chain reaction that will send everyone into the volcano because they see no blue dots and they assume its them.
 

Knownothing

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Nov 22, 2006
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They tell the guys wearing black and gold that it is them who has the blue dot. Then all the red dots sit around and laugh the next day after dawn.
 

sodakjoe

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Sep 15, 2006
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The Monty Hall problem post reminded me of another puzzle.

A man is shipwrecked on a remote island. The inhabitants of this island are born with either a red dot or a blue dot on their forehead and they never discuss the color of their dot. In fact, their religion states that if they figure out what color dot they have they must throw themselves in the volcano at dawn the next morning. The people also have perfect logic and deductive reasoning skills. After a few weeks the shipwrecked man builds a new boat and one day at noon he leaves. All the natives are present to see the stranger off, and just as he is leaving he says "At least one of you has a blue dot".

What happens?

I'm pretty sure you're missing part of the problem, because the solution to a riddle extremely similar to this involves the number of people on the island.
 

everyyard

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If only one had a blue dot the rest would know they had a red dot thus everyone killing themself.

no, he said at least one...which could be more. the only way they all die is by none having a blue dot so they all must assume they are the one.
 

jdoggivjc

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Sep 27, 2006
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If only one had a blue dot the rest would know they had a red dot thus everyone killing themself.

Not necessarily. Before the guy left he said "AT LEAST one." He didn't say "ONLY one." That one person with the blue dot would commit suicide. However, because the guy said "AT LEAST one", the rest of the people on the island would not know if they were a second person with the blue dot on their head or if the remaining people on the island had a red dot - therefore they wouldn't know if they had a red dot or blue dot on their head, and wouldn't have to commit suicide.
 

247cy

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Nov 14, 2006
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Spring Hill, KS
The Monty Hall problem post reminded me of another puzzle.

A man is shipwrecked on a remote island. The inhabitants of this island are born with either a red dot or a blue dot on their forehead and they never discuss the color of their dot. In fact, their religion states that if they figure out what color dot they have they must throw themselves in the volcano at dawn the next morning. The people also have perfect logic and deductive reasoning skills. After a few weeks the shipwrecked man builds a new boat and one day at noon he leaves. All the natives are present to see the stranger off, and just as he is leaving he says "At least one of you has a blue dot".

What happens?

Obviously they cast aside the red dot/blue dot religion and begin worshiping a boat man deity - often building replica boats on the shore in hopes their god will return.
 

DaddyMac

Well-Known Member
Oct 18, 2006
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The Monty Hall problem post reminded me of another puzzle.

A man is shipwrecked on a remote island. The inhabitants of this island are born with either a red dot or a blue dot on their forehead and they never discuss the color of their dot. In fact, their religion states that if they figure out what color dot they have they must throw themselves in the volcano at dawn the next morning. The people also have perfect logic and deductive reasoning skills. After a few weeks the shipwrecked man builds a new boat and one day at noon he leaves. All the natives are present to see the stranger off, and just as he is leaving he says "At least one of you has a blue dot".

What happens?

A bunch of suckers on Cyclone Fanatic try and piece together the fictional events on a ficticous island inhabited by people with a most unfortunate skin condition?
 

egami

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May 19, 2009
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There are no female inhabitants.......didn't you read the story?

"The people also have perfect logic and deductive reasoning skills."

rofl...I can't bump you for that one yet...hate the stupid limitations on that here.
 

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