Brain Teasers

[Kwhit10]

How about the easy one?



" A man lives on the 20th floor.  Everyday, he takes the elevator down to the ground.  When he returns, he takes the elevator to the 11th floor, and walks up the other 9 floors, except when it rains.  Then he takes the elevator up to the 2oth floor"

He's a midget he can't reach he 20th floor button, so he goes to the highest floor for which button he can reach, when it rains he has an umbrella.

[wdleehi]

How about the easy one?



" A man lives on the 20th floor.  Everyday, he takes the elevator down to the ground.  When he returns, he takes the elevator to the 11th floor, and walks up the other 9 floors, except when it rains.  Then he takes the elevator up to the 2oth floor"

He's a midget he can't reach he 20th floor button, so he goes to the highest floor for which button he can reach, when it rains he has an umbrella.

Yep.

[popeyejones]

What would the other guard say if I asked him what is behind his door? The good one knows that the liar will say heaven, the bad one knows that the good one will say heaven, but lie about it and say hell.

Their answers reveal what's behind them.

Not quite, it's a very good guess though. And on the right track I guess, and as I said, it's a yes or no question.

P.S. your answer is incorrect, I'm not saying it's wrong because it's not what I'm looking for.

"Would the other guard tell me that this door leads to heaven?"

Both the angel and devil would give the same answer, so that wouldn't work.

Doesn't matter who answers it or which door they are guarding. If they say 'yes' then the door behind him is to heaven, if 'no', then it's to hell, in which case the other door would be taken.

Just to clarify, both answers are correct but they work differently.

If you ask "would the other guard tell me that this door leads to heaven" then you are looking for the answer 'no.'  Whoever says 'no' guards the door to heaven and whoever says 'yes' guards the door to hell.

If you ask "does the devil guard the door to hell" you are looking for the answer 'yes.'  Whoever says 'yes' is guarding the door to heaven and whoever says 'no' guards the door to hell.

In neither case can you determine who is the angel and who is the devil.  But in both cases you can determine which door is heaven and which is hell.

[guava_wrench]

What would the other guard say if I asked him what is behind his door? The good one knows that the liar will say heaven, the bad one knows that the good one will say heaven, but lie about it and say hell.

Their answers reveal what's behind them.

Not quite, it's a very good guess though. And on the right track I guess, and as I said, it's a yes or no question.

P.S. your answer is incorrect, I'm not saying it's wrong because it's not what I'm looking for.

"Would the other guard tell me that this door leads to heaven?"

Both the angel and devil would give the same answer, so that wouldn't work.

Doesn't matter who answers it or which door they are guarding. If they say 'yes' then the door behind him is to heaven, if 'no', then it's to hell, in which case the other door would be taken.

See I don't get it (but maybe I'm just slow), I don't think this works.

This guy doesn't know who the angel is and who the devil is, also he doesn't know which door each is guarding.
If the guy asks the devil "would the other guard tell me that this door leads to heaven" and it does, then the devil would say no (it still doens't reveal if that is the truth or if that is a lie).
If the guy asks the angel "would the other guard tell me that this door leads to heaven" and it does, then the angel would say no (it still doens't reveal if that is the truth or if that is a lie).

You still don't know what door to go through.

You know which door because the answer you get is always wrong! If they say no to that door, than that is the door. If they say yes, than it is the other door.

The trick behind the answer is to make sure that either questionee will give an answer that will introduce the same # of negations. If you want the correct door answer instead of the negation, ask 2 more levels of indirection:

"Will the other guy say that you will say that the other guy will say that this is the door to heaven?"

I actually heard this one as more of a Turing test, with a truthful and a lying computer, a single keyboard, and a random KVM - you don't know which computer will answer. You are trapped in a room with with 2 doors, one which leads to freedom, one which triggers a bomb if you touch it. You can only type 1 yes/know question. What question do you type into the keyboard?

[guava_wrench]

What would the other guard say if I asked him what is behind his door? The good one knows that the liar will say heaven, the bad one knows that the good one will say heaven, but lie about it and say hell.

Their answers reveal what's behind them.

Not quite, it's a very good guess though. And on the right track I guess, and as I said, it's a yes or no question.

P.S. your answer is incorrect, I'm not saying it's wrong because it's not what I'm looking for.

"Would the other guard tell me that this door leads to heaven?"

Both the angel and devil would give the same answer, so that wouldn't work.

Doesn't matter who answers it or which door they are guarding. If they say 'yes' then the door behind him is to heaven, if 'no', then it's to hell, in which case the other door would be taken.

Just to clarify, both answers are correct but they work differently.

If you ask "would the other guard tell me that this door leads to heaven" then you are looking for the answer 'no.'  Whoever says 'no' guards the door to heaven and whoever says 'yes' guards the door to hell.

If you ask "does the devil guard the door to hell" you are looking for the answer 'yes.'  Whoever says 'yes' is guarding the door to heaven and whoever says 'no' guards the door to hell.

In neither case can you determine who is the angel and who is the devil.  But in both cases you can determine which door is heaven and which is hell.

The second case is why this version seems messier that the computer version.  The second case doesn't actually work, since the original posing of the puzzle said you don't know who guards what. Otherwise, any question with a know answer would work (is 1 + 1 = 2?)

If you it is the case that you don't know what they are guarding, then, intuitively, they aren't actually guards, are they?

[SShoreFan 2.0]

An archeologist discovers a sealed cave.

Upon opening it, he looks in, shines his flashlight around and sees two perfectly preserved unclothed bodies...one male and one female.

He then re-seals the cave and publishes a paper, describing his findings, in a scientific journal.

He claims that he has discovered the bodies of Adam and Eve, and that his brief look inside the cave yielded indisputable proof of their identity.

What is the proof?

They didn't have belly buttons!

A TP for you, sir!

Ahhh, not fair, we need to make these things "heathen friendly"!!   

[wdleehi]

Here is the one I have had no one ever solve.  (I am not sure how I solved it.  My friends asked me this on my birthday and I spent all night asking questions to solve it, and thus, didn't study or my final the next day)




"A man goes into a restaurant in Alaska.  He orders a bird for diner.  He takes one bite of it, and then, goes outside and shoots himself in the head."  What happened?

[popeyejones]

Here is the one I have had no one ever solve.  (I am not sure how I solved it.  My friends asked me this on my birthday and I spent all night asking questions to solve it, and thus, didn't study or my final the next day)




"A man goes into a restaurant in Alaska.  He orders a bird for diner.  He takes one bite of it, and then, goes outside and shoots himself in the head."  What happened?

I've heard this one before.  It is pretty drawn out and somewhat gruesome, IIRC.

[wdleehi]

Here is the one I have had no one ever solve.  (I am not sure how I solved it.  My friends asked me this on my birthday and I spent all night asking questions to solve it, and thus, didn't study or my final the next day)




"A man goes into a restaurant in Alaska.  He orders a bird for diner.  He takes one bite of it, and then, goes outside and shoots himself in the head."  What happened?

I've heard this one before.  It is pretty drawn out and somewhat gruesome, IIRC.

Yep.  And it takes a lot of random questions to figure it out.

[popeyejones]

Here is one of my all time favorites. 


There is an ancient monarchy with a dying queen.  She has no heirs.  She wishes to find a wise person to assume the throne after she dies.  So she devises a plan.  After scouring the country’s universities, boardrooms, clown colleges and internet message boards she comes up with a list of three people that she deems fit to rule.  One woman, one man, and one extremely precocious eight-year-old with a broadband connection.  She brings them into her throne room and tells them that she has devised a plan to determine who will assume the throne when she dies.  What follows is more or less an exact account of what she said.
“Greetings my pretties.  I made up a little game for you.  I have in my hand a bag.  In that bag there are small hats.  Five small hats, to be exact.  Each hat is one color and one color only, white or black.  Three of the hats are black and two are white.  I am going to turn out the lights in my chamber and it will be completely dark.  I have some dope night vision goggles so I’ll be able to see fine but none of you will be able to see a thing.  I am going to line you up in a row facing me so that once the lights are back on, the first person in the line can see only me, the second person in the line can see the person in front of her/him/it and me.  The third person in line will be the lucky one, he/she/it will be able to see both people in front of them as well as me. 

“Now then.  Once you are in line I will bring the bag to you and you will reach in and put one and only one hat on your head.  Once you each have a hat on your head I will put you in line just as I described.  I will also have the remaining hats incinerated so that nobody will know what was left in the bag (but I will take care to remove my dope night vision goggles before doing so: I am a wise queen after all).  I will then turn on the lights in my throne room.  None of you will be allowed to move from your position, reach for the hat on your head, or speak to eachother.  If you do so you will be executed immediately.  The first one of you to correctly tell me what color hat you are wearing will be my heir.  If you are wrong you will be executed immediately.”

The queen proceeded to do this just like she said.  And everything went according to plan.  Everybody lined up with a hat on their head.  Nothing happened at first, but after about five minutes the extremely precocious eight-year-old—who was standing at the front of the line—raised it’s hand and correctly told the queen what color hat it was wearing.

What color was the hat and how do you/did it know?

[CelticsWhat35]

Here is the one I have had no one ever solve.  (I am not sure how I solved it.  My friends asked me this on my birthday and I spent all night asking questions to solve it, and thus, didn't study or my final the next day)




"A man goes into a restaurant in Alaska.  He orders a bird for diner.  He takes one bite of it, and then, goes outside and shoots himself in the head."  What happened?

Alrite, 20 questions time.  Is the man allergic to what he ate?

[wdleehi]

Here is one of my all time favorites. 


There is an ancient monarchy with a dying queen.  She has no heirs.  She wishes to find a wise person to assume the throne after she dies.  So she devises a plan.  After scouring the country’s universities, boardrooms, clown colleges and internet message boards she comes up with a list of three people that she deems fit to rule.  One woman, one man, and one extremely precocious eight-year-old with a broadband connection.  She brings them into her throne room and tells them that she has devised a plan to determine who will assume the throne when she dies.  What follows is more or less an exact account of what she said.
“Greetings my pretties.  I made up a little game for you.  I have in my hand a bag.  In that bag there are small hats.  Five small hats, to be exact.  Each hat is one color and one color only, white or black.  Three of the hats are black and two are white.  I am going to turn out the lights in my chamber and it will be completely dark.  I have some dope night vision goggles so I’ll be able to see fine but none of you will be able to see a thing.  I am going to line you up in a row facing me so that once the lights are back on, the first person in the line can see only me, the second person in the line can see the person in front of her/him/it and me.  The third person in line will be the lucky one, he/she/it will be able to see both people in front of them as well as me. 

“Now then.  Once you are in line I will bring the bag to you and you will reach in and put one and only one hat on your head.  Once you each have a hat on your head I will put you in line just as I described.  I will also have the remaining hats incinerated so that nobody will know what was left in the bag (but I will take care to remove my dope night vision goggles before doing so: I am a wise queen after all).  I will then turn on the lights in my throne room.  None of you will be allowed to move from your position, reach for the hat on your head, or speak to eachother.  If you do so you will be executed immediately.  The first one of you to correctly tell me what color hat you are wearing will be my heir.  If you are wrong you will be executed immediately.”

The queen proceeded to do this just like she said.  And everything went according to plan.  Everybody lined up with a hat on their head.  Nothing happened at first, but after about five minutes the extremely precocious eight-year-old—who was standing at the front of the line—raised it’s hand and correctly told the queen what color hat it was wearing.

What color was the hat and how do you/did it know?

The Black Hat because his head started heating up.

[wdleehi]

Here is the one I have had no one ever solve.  (I am not sure how I solved it.  My friends asked me this on my birthday and I spent all night asking questions to solve it, and thus, didn't study or my final the next day)




"A man goes into a restaurant in Alaska.  He orders a bird for diner.  He takes one bite of it, and then, goes outside and shoots himself in the head."  What happened?

Alrite, 20 questions time.  Is the man allergic to what he ate?

no

[popeyejones]

Here is one of my all time favorites. 


There is an ancient monarchy with a dying queen.  She has no heirs.  She wishes to find a wise person to assume the throne after she dies.  So she devises a plan.  After scouring the country’s universities, boardrooms, clown colleges and internet message boards she comes up with a list of three people that she deems fit to rule.  One woman, one man, and one extremely precocious eight-year-old with a broadband connection.  She brings them into her throne room and tells them that she has devised a plan to determine who will assume the throne when she dies.  What follows is more or less an exact account of what she said.
“Greetings my pretties.  I made up a little game for you.  I have in my hand a bag.  In that bag there are small hats.  Five small hats, to be exact.  Each hat is one color and one color only, white or black.  Three of the hats are black and two are white.  I am going to turn out the lights in my chamber and it will be completely dark.  I have some dope night vision goggles so I’ll be able to see fine but none of you will be able to see a thing.  I am going to line you up in a row facing me so that once the lights are back on, the first person in the line can see only me, the second person in the line can see the person in front of her/him/it and me.  The third person in line will be the lucky one, he/she/it will be able to see both people in front of them as well as me. 

“Now then.  Once you are in line I will bring the bag to you and you will reach in and put one and only one hat on your head.  Once you each have a hat on your head I will put you in line just as I described.  I will also have the remaining hats incinerated so that nobody will know what was left in the bag (but I will take care to remove my dope night vision goggles before doing so: I am a wise queen after all).  I will then turn on the lights in my throne room.  None of you will be allowed to move from your position, reach for the hat on your head, or speak to eachother.  If you do so you will be executed immediately.  The first one of you to correctly tell me what color hat you are wearing will be my heir.  If you are wrong you will be executed immediately.”

The queen proceeded to do this just like she said.  And everything went according to plan.  Everybody lined up with a hat on their head.  Nothing happened at first, but after about five minutes the extremely precocious eight-year-old—who was standing at the front of the line—raised it’s hand and correctly told the queen what color hat it was wearing.

What color was the hat and how do you/did it know?

The Black Hat because his head started heating up.

Nice try. 

There are no tricks to this one.  Just use your logic.

[CelticsWhat35]

Is the eight year old a dog?