There is a five story building. On the ground floor there are three light switches, one of which turns on the light on the fifth floor. You can only flip on two switches at once, and there is no way to see whether or not the lights are on upstairs without going up to check. You are only allowed to go up and check once. How can you tell which switch is the one that works?
I can answer this, but I need to assume that there are also lights in the room the switches are in (and that I can see the lights in the switch room being turned on and off).
Nope. No lights in the switch room. (Guess you're using a flashlight or have night vision or something. 
) But I'd like to hear how you'd accomplish it with your idea-I haven't a clue how you'd use the lights downstairs to help.
) But I'd like to hear how you'd accomplish it with your idea-I haven't a clue how you'd use the lights downstairs to help.
turn on two switches for ten minutes.. then turn off one
run up stairs.. if lights are on then the one you left on is the switch..
if lights are off but warm it is the switch you turned on and off after ten minutes.
if lights off and cool you can label the last switch you didnt touch as the one.
run up stairs.. if lights are on then the one you left on is the switch..
if lights are off but warm it is the switch you turned on and off after ten minutes.
if lights off and cool you can label the last switch you didnt touch as the one.
Ahh, phooey. You're right. 
Hoped it'd be harder to get.
Hoped it'd be harder to get.
lol it is hard just i have heard that one before..
here is one for ya
you are a hermit and moving to another island
you have three pets.. a bear, a cat and a dog
you boat can only hold one at a time
and you cant leave the bear alone with either of them or it will kill them
whats the best way to get all the animals to the new island?
here is one for ya
you are a hermit and moving to another island
you have three pets.. a bear, a cat and a dog
you boat can only hold one at a time
and you cant leave the bear alone with either of them or it will kill them
whats the best way to get all the animals to the new island?
Take the bear over first, leave it on the island, go back for the dog,
come to the island with the dog and pick up the bear and take it back with you to get the cat,
drop the bear off, take the cat over to the island, then come back and pick up the bear.
Whew! I'd just not have any bears as pets myself...
come to the island with the dog and pick up the bear and take it back with you to get the cat,
drop the bear off, take the cat over to the island, then come back and pick up the bear.
Whew! I'd just not have any bears as pets myself...
Wont the dog attack the cat?
its a stupid dog.. but your gith it is supposed to be the dog will eat the cat and the bear will eat the dog but not the cat.
so you take the dog first.. leave bear and cat.. come back get bear.. drop off bear pcik up dog.. leave doig and get cat and drop cat off with bear and then just leave your dog on the other island as it is alot of work.
draw 9 smilies
can you connect the smilies by drawing four straight lines and never let your pen leave the page and your pen cant draw back on itself.. meaning the lines can cross but you cant go back along a line.. so no to three lines done and a line along the bottom.
so you take the dog first.. leave bear and cat.. come back get bear.. drop off bear pcik up dog.. leave doig and get cat and drop cat off with bear and then just leave your dog on the other island as it is alot of work.
draw 9 smilies
can you connect the smilies by drawing four straight lines and never let your pen leave the page and your pen cant draw back on itself.. meaning the lines can cross but you cant go back along a line.. so no to three lines done and a line along the bottom.
I put my ruler up to the smilies and I can do it with three lines that look something an off center 4. I had to go outside the frame though. Is that acceptable?
I also drew the circles on a paper and by folding the paper I was able to cross them all with one line. Then I got that paper and wrapped it around a paper towel roll and with one continuous line I crossed them all again. And finally by folding the paper so that they were all on top of each other I was able to cross them all by pushing my pencil through the paper so I guess you could say I affected or altered them without drawing any lines at all.
Uh oh this sounds like we're getting into that quantum thing here
Here's one: You have two guys guarding two roads. One road leads to a town and the other leads to nowhere. One of the guards always lies and the other always tells the truth and of course you don't know which is which. You want to go to the town and you could only ask one guard one question. What would you ask in order to get on the correct road.
I also drew the circles on a paper and by folding the paper I was able to cross them all with one line. Then I got that paper and wrapped it around a paper towel roll and with one continuous line I crossed them all again. And finally by folding the paper so that they were all on top of each other I was able to cross them all by pushing my pencil through the paper so I guess you could say I affected or altered them without drawing any lines at all.
Uh oh this sounds like we're getting into that quantum thing here
Here's one: You have two guys guarding two roads. One road leads to a town and the other leads to nowhere. One of the guards always lies and the other always tells the truth and of course you don't know which is which. You want to go to the town and you could only ask one guard one question. What would you ask in order to get on the correct road.
Yes... but what if the switch were on a conveyor and the lightbulb was set to match the speed of the stairs exactly?
I know this one as well but will alllow others to thunk on it. but i am pretty sure they know who the liar is.
yeah you are right i believe in how you say you solved my puzzle that is if you got something like the picture below
yeah you are right i believe in how you say you solved my puzzle that is if you got something like the picture below
i am not sure what you mean by the switch is on a coveyor but it sounds like i would go find the guy that designed the building and punch him in the face.
Oh goodness, the plane on a conveyer belt thread will never die! (LOL)
Here's a simple one.
Guy gets a call from his friends to go out to the pub. He agrees, turns out the light, locks the door and goes and has a good time. When he returns, we he is surrounded with death and destruction.
What happened?
Here's a simple one.
Guy gets a call from his friends to go out to the pub. He agrees, turns out the light, locks the door and goes and has a good time. When he returns, we he is surrounded with death and destruction.
What happened?
He forgot to turn off the news.
QUOTE (j6p+Jan 31 2006, 09:27 AM)
Here's one: You have two guys guarding two roads. One road leads to a town and the other leads to nowhere. One of the guards always lies and the other always tells the truth and of course you don't know which is which. You want to go to the town and you could only ask one guard one question. What would you ask in order to get on the correct road.
Ask either guard which road the other guard would tell you to take. Then take the other road.
Ask either guard which road the other guard would tell you to take. Then take the other road.
Nice, but not what I'm looking for. I could state more clearly, he was surrounded as in, there were dead bodies physically there
regarding Q about two guards (missed it first time) I would ask one guard if the other guard would tell me if this partiular road leads to town.
I would ask something like:
"If I ask the other guard, if this road leads to town, would he answer yes?"
If my road choice is wrong + I talked to liar, then other guard would say no, liar twists to yes.
If my road choice is wrong + I talked to truthful, then other guard would yes, so truthful would say yes.
If my road choice is correct + I talked to liar, then other guard would say yes, liar would twist to no.
If my road choice is correct + I talked to truthful, other guard would say no, so answer would be no.
Therefore, if I get back yes, then I take the other road. If I get back no, then I take the road I choose.
I hope my logic is correct that.. thats a weird one!
regarding Q about two guards (missed it first time) I would ask one guard if the other guard would tell me if this partiular road leads to town.
I would ask something like:
"If I ask the other guard, if this road leads to town, would he answer yes?"
If my road choice is wrong + I talked to liar, then other guard would say no, liar twists to yes.
If my road choice is wrong + I talked to truthful, then other guard would yes, so truthful would say yes.
If my road choice is correct + I talked to liar, then other guard would say yes, liar would twist to no.
If my road choice is correct + I talked to truthful, other guard would say no, so answer would be no.
Therefore, if I get back yes, then I take the other road. If I get back no, then I take the road I choose.
I hope my logic is correct that.. thats a weird one!
Same thing.. ask either guard which road the other guard would tell you to take.
Guard says, "He would tell you to take road A."
If the guard is the liar, that means the truthteller would truthfully tell you to take B into town.
If the guard is the truthteller, that means the liar would falsely tell you to take road A to oblivion.
Either way, take road B.
Guard says, "He would tell you to take road A."
If the guard is the liar, that means the truthteller would truthfully tell you to take B into town.
If the guard is the truthteller, that means the liar would falsely tell you to take road A to oblivion.
Either way, take road B.
QUOTE (Insyght+Jan 31 2006, 04:10 PM)
Guy gets a call from his friends to go out to the pub. He agrees, turns out the light, locks the door and goes and has a good time. When he returns, we he is surrounded with death and destruction.
What happened?
He's a butcher???
the us thinks he has wmd's
or he has two dogs one called death and the other destruction
or he lives at a light house and shouldnt have turned out the lights which is what i think he is looking for.
or he has two dogs one called death and the other destruction
or he lives at a light house and shouldnt have turned out the lights which is what i think he is looking for.
JoulesBeef,
No one ever got it that fast. Nice.
He lives in a white has and turned out "the light" (LOL).
Yes, you can kick me now...
No one ever got it that fast. Nice.
He lives in a white has and turned out "the light" (LOL).
Yes, you can kick me now...
This is a great thread. I hope it lays to rest that airplane one. As for the answer to the "two guards" riddle, Insyght and gmilam are right on the money.
Found this interesting paradox...
The Racetrack (or Dichotomy)
One can never reach the end of a racecourse, for in order to do so one would first have to reach the halfway mark, then the halfway mark of the remaining half, then the halfway mark of the final fourth, then of the final eighth, and so on ad infinitum. Since this series of fractions is infinite, one can never hope to get through the entire length of the track (at least not in a finite time).
Start ____________________1/2__________3/4_____7/8__15/16... Finish
But things get even worse than this. Just as one cannot reach the end of the racecourse, one cannot even begin to run. For before one could reach the halfway point, one would have to reach the 1/4 mark, and before that the 1/8 mark, etc., etc. As there is no first point in this series, one can never really get started (this is known as the Reverse Dichotomy).
Wierd. Found lots of this stuff by google searching for "mind puzzles."
The Racetrack (or Dichotomy)
One can never reach the end of a racecourse, for in order to do so one would first have to reach the halfway mark, then the halfway mark of the remaining half, then the halfway mark of the final fourth, then of the final eighth, and so on ad infinitum. Since this series of fractions is infinite, one can never hope to get through the entire length of the track (at least not in a finite time).
Start ____________________1/2__________3/4_____7/8__15/16... Finish
But things get even worse than this. Just as one cannot reach the end of the racecourse, one cannot even begin to run. For before one could reach the halfway point, one would have to reach the 1/4 mark, and before that the 1/8 mark, etc., etc. As there is no first point in this series, one can never really get started (this is known as the Reverse Dichotomy).
Wierd.
Found lots of this stuff by google searching for "mind puzzles."
answer to race track
once he gets to 99% done he will be done.
conjecture track is one mile, you say he can never reach the end because of forever smaller steps.. i say he reaches the end when he is close enough it doesnt matter or travelling .999999... miles is the same as traveling 1 mile.
proof
x=.9999999....
10x=9.99999999....
10x-x=9.999999.....-.999999999.....
9x=9
x=1
.999999......=1
ok another one...
3 guys on a trip decide to split a room
the bell boy sets them up with a room and collects $10 from each of them
he brings the $30 to the manager, who gives him $5 change as the room is only $25.
the belboy quickly realises that he cant divide the $5 betwen the three men and pockets $2 and gives each man a dollar back.
so each man paid $9 for the room. totaled that is $27 plus the $2 the bell boy took is only $29 what happen to the lost dollar?
once he gets to 99% done he will be done.
conjecture track is one mile, you say he can never reach the end because of forever smaller steps.. i say he reaches the end when he is close enough it doesnt matter or travelling .999999... miles is the same as traveling 1 mile.
proof
x=.9999999....
10x=9.99999999....
10x-x=9.999999.....-.999999999.....
9x=9
x=1
.999999......=1
ok another one...
3 guys on a trip decide to split a room
the bell boy sets them up with a room and collects $10 from each of them
he brings the $30 to the manager, who gives him $5 change as the room is only $25.
the belboy quickly realises that he cant divide the $5 betwen the three men and pockets $2 and gives each man a dollar back.
so each man paid $9 for the room. totaled that is $27 plus the $2 the bell boy took is only $29 what happen to the lost dollar?
hotel problem:
The $27 is including what the bellboy took. Each man payed ten dollars and got a total of three dollars back. The bellboy took 2 dollars. 3 + 2 = $5 so 25 + 5 = $30.
The $27 is including what the bellboy took. Each man payed ten dollars and got a total of three dollars back. The bellboy took 2 dollars. 3 + 2 = $5 so 25 + 5 = $30.
But what if the three guys paid the desk clerk $9.00 each and tipped the bellboy $2.00, that would add up to $29.00.
In actuality they did pay $9.00 each because if you pay $10.00 and get a dollar rebate you end up paying $9.00. And instead of tipping the bellboy $2.00, he stole $2.00. I can't see the difference here.
So the question stands: Where is the $1.00? Did it take off and fly or not
In actuality they did pay $9.00 each because if you pay $10.00 and get a dollar rebate you end up paying $9.00. And instead of tipping the bellboy $2.00, he stole $2.00. I can't see the difference here.
So the question stands: Where is the $1.00? Did it take off and fly or not
QUOTE
But what if the three guys paid the desk clerk $9.00 each and tipped the bellboy $2.00, that would add up to $29.00.
In actuality they did pay $9.00 each because if you pay $10.00 and get a dollar rebate you end up paying $9.00. And instead of tipping the bellboy $2.00, he stole $2.00. I can't see the difference here.
So the question stands: Where is the $1.00? Did it take off and fly or not
In actuality they did pay $9.00 each because if you pay $10.00 and get a dollar rebate you end up paying $9.00. And instead of tipping the bellboy $2.00, he stole $2.00. I can't see the difference here.
So the question stands: Where is the $1.00? Did it take off and fly or not
And what if they tipped him $5? or $10? Then you get 9 x 3 + 10, which equals $37, which has absolutely nothing to do with the question whatsoever. They paid $10 each. The change was then divided up into $2 for the bellboy and $1 each for each guy. You wouldn't add the $2, you subtract it.
What if the bell hop rides a escalator up to their rooms and the escalator has a control which matches his speed then the...
The men paid $27.
We know this is true
The desk clerk has 25
While the bell hop pocketed 2.
We know this is true
The desk clerk has 25
While the bell hop pocketed 2.
QUOTE
While the bell hop pocketed 2.
Of the change, not the original payment. The men payed $27. The cost is $25. The extra $2 the men payed went to the bell hop. 27 - 2 = 25.
QUOTE (JoulesBeef+Feb 6 2006, 04:26 AM)
3 guys on a trip decide to split a room
the bell boy sets them up with a room and collects $10 from each of them
he brings the $30 to the manager, who gives him $5 change as the room is only $25.
the belboy quickly realises that he cant divide the $5 betwen the three men and pockets $2 and gives each man a dollar back.
so each man paid $9 for the room. totaled that is $27 plus the $2 the bell boy took is only $29 what happen to the lost dollar?
It is deceptive at first, I'll give you that.
But in the end they paid $27 in total: $25 for the room, $2 to the bell boy.
The two dollars the bell boy took doesn't get added to the $27 they paid (not again any way, it's all ready been added in since they only got 3$ back from $30 in stead of $5) so they paid: $25 desk+$2 bell boy=$27, not $25 desk+$2 bell boy+$2 bell boy=$29.
the bell boy sets them up with a room and collects $10 from each of them
he brings the $30 to the manager, who gives him $5 change as the room is only $25.
the belboy quickly realises that he cant divide the $5 betwen the three men and pockets $2 and gives each man a dollar back.
so each man paid $9 for the room. totaled that is $27 plus the $2 the bell boy took is only $29 what happen to the lost dollar?
It is deceptive at first, I'll give you that.
But in the end they paid $27 in total: $25 for the room, $2 to the bell boy.
The two dollars the bell boy took doesn't get added to the $27 they paid (not again any way, it's all ready been added in since they only got 3$ back from $30 in stead of $5) so they paid: $25 desk+$2 bell boy=$27, not $25 desk+$2 bell boy+$2 bell boy=$29.
...or I guess I basically I agree with what a bunch of other people already said...
seems like a lot of these types of problems are like "pea and shell" games, they try to confuse the reader or spectator. They can be fun though...
seems like a lot of these types of problems are like "pea and shell" games, they try to confuse the reader or spectator. They can be fun though...
it doesn't even need thinking about
you are counting in both directions up and down as an example count the number of fingers on your left hand upwards 1,2... then count the fingers on your right hand downwards 10,9... and add the two results and for those with limited resources this equals 11.
AR
you are counting in both directions up and down as an example count the number of fingers on your left hand upwards 1,2... then count the fingers on your right hand downwards 10,9... and add the two results and for those with limited resources this equals 11.
AR
yeah i don't think i worded the puzzle quite right and it is old
but yeah your all right...
OK not really a puzzle
take a wheel with a one meter circumference and roll it on the ground for one rotation and it will draw a line one meter
take another wheel 1.5 meters and it will draw a l.5 meter line
now glue the 1 meter wheel to the center of the 1.5 meter wheel
why are the two lines below equal
another strange thing similar
draw a line the circumference of a quarter(or what ever large coin currency you have two of).. don't know how? ink up the quarter and roll it one revolution..
now each time you roll a quarter down this line it will complete one revolution.
now place the quarter on the table.. take another quarter and roll it around the circumference of the original quarter... why does it revolve twice going around the quarter?
ok and last a bit stupid math
x,y,z are all different integers such that
z=(x+y+z)/x*y
y=(Y+x+z)/z*x
and
x+y+z=x*y*z
whats x,y and z
but yeah your all right...
OK not really a puzzle
take a wheel with a one meter circumference and roll it on the ground for one rotation and it will draw a line one meter
take another wheel 1.5 meters and it will draw a l.5 meter line
now glue the 1 meter wheel to the center of the 1.5 meter wheel
why are the two lines below equal
another strange thing similar
draw a line the circumference of a quarter(or what ever large coin currency you have two of).. don't know how? ink up the quarter and roll it one revolution..
now each time you roll a quarter down this line it will complete one revolution.
now place the quarter on the table.. take another quarter and roll it around the circumference of the original quarter... why does it revolve twice going around the quarter?
ok and last a bit stupid math
x,y,z are all different integers such that
z=(x+y+z)/x*y
y=(Y+x+z)/z*x
and
x+y+z=x*y*z
whats x,y and z
That first one is pretty good. I won't open this thread again until I figure it out.
x = 1
y = 2
z = 3
y = 2
z = 3
The lines may be equal in length but they don't equal the circumference of their accompanying circles. The graphics are decieving.
I think I figured it out. The answers involve infinite points (there are the same number of 'points' in each circle, ie, infinite) and trigonometery. Any discrete point will be mapped to a 'larger' point on the outer circle, because a circle is made up of triangles, but an infinite number of them.
Okay, that's not a mathematical proof at all. But at least I solved it in my own head!
Okay, that's not a mathematical proof at all. But at least I solved it in my own head!
The line shows how far the circle has translated not how far a point on the circle has moved. The center translates the amount same for both.
Since the outer circle is larger the outside points move faster than the inner points except for the lowest points which don't move when compared to the ground (not a conveyor). Thus a point on the outer circle travels farther in the same amount time.
Since the outer circle is larger the outside points move faster than the inner points except for the lowest points which don't move when compared to the ground (not a conveyor). Thus a point on the outer circle travels farther in the same amount time.
in the circumference problem involving equal lines, the outer circumference is actually "skidding" around the revolution. The smaller circumference is actually doing the tracing.
By moving the center of the smaller circle by r2-r1, you've made the angular diameters equal. arctan(diameter/distance).
Guest, has it right, "in the circumference problem involving equal lines, the outer circumference is actually "skidding" around the revolution. The smaller circumference is actually doing the tracing.
I reread my post and I had to edit it.
Actually if the outer circle is making the trace, the inner circle is skidding and if the inner circle is making the trace the outer circle is skidding. One of them has to skid.
I reread my post and I had to edit it.
Actually if the outer circle is making the trace, the inner circle is skidding and if the inner circle is making the trace the outer circle is skidding. One of them has to skid.
Hey! Found another puzzle:
At a local bar, three friends, Mr. Green, Mr. Red and Mr. Blue, were having a drink. One man was wearing a red suit; one a green suit; and the other a blue suit. "Have you noticed," said the man in the blue suit, "that although our suits have colors corresponding to our names, not one of us is wearing a suit that matches our own names?" Mr. Red looked at the other two and said, "You're absolutely correct."
What color suit is each man wearing?
At a local bar, three friends, Mr. Green, Mr. Red and Mr. Blue, were having a drink. One man was wearing a red suit; one a green suit; and the other a blue suit. "Have you noticed," said the man in the blue suit, "that although our suits have colors corresponding to our names, not one of us is wearing a suit that matches our own names?" Mr. Red looked at the other two and said, "You're absolutely correct."
What color suit is each man wearing?
blue suit is not mr. blue, and is not mr. red, blue suit is mr. green
red suit is not mr. red, mr. green is already taken. He is mr. Blue
so green suit is mr. red
red suit is not mr. red, mr. green is already taken. He is mr. Blue
so green suit is mr. red
The puzzle can be solved based upon to observations.
1. the man in the blue suit observed that none of the three men wear suit's of their namesake.
2. Mr Red looks at his fellow bar flies and observed that what the man in the bule suit said is correct.
given these two observations you can conclude that Mr Green is wearing a red suit, Mr Red is wearing a blue suit and Mr Blue is wearing a green suit
1. the man in the blue suit observed that none of the three men wear suit's of their namesake.
2. Mr Red looks at his fellow bar flies and observed that what the man in the bule suit said is correct.
given these two observations you can conclude that Mr Green is wearing a red suit, Mr Red is wearing a blue suit and Mr Blue is wearing a green suit
"Actually if the outer circle is making the trace, the inner circle is skidding and if the inner circle is making the trace the outer circle is skidding. One of them has to skid. "
Note that both of them could be skidding simultaneously. It doesn't have to be one or the other.
Note that both of them could be skidding simultaneously. It doesn't have to be one or the other.
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