| 12 JAN 2003 at 12:36am |
Agustín CordesGuild Master
Posts : 5696
Joined: 23 OCT 2002
Location: AR, Buenos Aires
Status : Offline | Four!
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| 12 JAN 2003 at 12:51am |
szcaxJourneyman
Posts : 935
Joined: 12 OCT 2002
Status : Online | 11
Black holes are where God divided by zero
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| 12 JAN 2003 at 1:23am |
BelindaSchattenjger
Posts : 2093
Joined: 21 OCT 2002
Status : Online | Sorry Rael........
szcax......you're right.....all of the months except Feb.
Next question.........
Two fathers & two sons went into a bar to have a Friday night drink together. They spent $15. Each spent the same amount. How much did each man spend?
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| 12 JAN 2003 at 1:36am |
ElfstoneGuild Master
Posts : 5892
Joined: 4 NOV 2002
Status : Online | $5
They were grandfather, father and son.
[b]playing[/b]: Destination Treasure Island (done in two sittings, but it's nice), Syberia (ho-hum), Dracula: Last Sanctuary (on hold)&&[b]reading[/b]: even more study papers&&[b]listening to[/b]: [url=http://www.last.fm/user/Brax82/]this and that[/url], plus [url=http://www.musicovery.com/]Musicovery[/url]&&[b]TV favorites[/b]: (currently) Pushing Daisies, Chuck, Journeyman (cancelled! grrr...), Heroes&& all-time) 24, Stargate SG1, X-Files, Lost, House
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| 12 JAN 2003 at 2:02am |
BelindaSchattenjger
Posts : 2093
Joined: 21 OCT 2002
Status : Online | Elfstone!! How did you know that one? You got the same book as I do.....heh
You are right Elfstone!
Another question.....
If a man lives in Seattle why can't he be buried in Birmingham?
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| 12 JAN 2003 at 2:12am |
InlandAZGuild Master
Posts : 5586
Joined: 4 MAY 2007
Status : Offline | Okay here's my contribution... It's not a trick question, and can be solved...
There are 12 pool balls on a table. In front of you is a common scale. One of the balls is a different weight - it may be heavier or may be lighter.
You may weigh any number of balls in any combination, but at the end of the third weighing you must know which is:
1.) The odd ball
2.) Was it lighter or heavier
Any takers?
This is a common test we give self procliamed "ace" programmers to make them feel humble... But, it can be done...
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| 12 JAN 2003 at 2:27am |
szcaxJourneyman
Posts : 935
Joined: 12 OCT 2002
Status : Online | Originally Posted By Belinda48 (12 JAN 2003 2:01am)
If a man lives in Seattle why can't he be buried in Birmingham?
Because.... he's still alive?
I just remember that from a riddle "if a plane crashes on the border between country x and country y, where are the survivors buried?" And naturally the answer is that survivors aren't buried.
Black holes are where God divided by zero
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| 12 JAN 2003 at 2:33am |
BelindaSchattenjger
Posts : 2093
Joined: 21 OCT 2002
Status : Online | yes szcax....because he is still alive.
Inland......that is a hard one......
Odd ball is the cue ball?
Another question..... ( you people here are smart)
In an orchestra there is something which is neither blown, bowed, plucked, or struck but without which the others could not play. What is it?
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| 12 JAN 2003 at 2:43am |
szcaxJourneyman
Posts : 935
Joined: 12 OCT 2002
Status : Online | Ok... here's a really tricky one...
There's a picture on this page
http://home.attbi.com/~n9ivo/whatswrong.swf
What's wrong with the picture?
you have to look really close. Some people have trouble seeing it, but when they finally notice it they feel soooo stupid for not seeing it before
Black holes are where God divided by zero
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| 12 JAN 2003 at 2:49am |
BelindaSchattenjger
Posts : 2093
Joined: 21 OCT 2002
Status : Online | szcax.....I've seen that one before.........LOL
I still went there anyways......and damnit, it still made me jump........
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| 12 JAN 2003 at 8:37am |
MichalNGrand Inquisitor
Posts : 7058
Joined: 14 SEP 2003
Status : Online | Originally Posted By Belinda48 (12 JAN 2003 1:23am)
Sorry Rael........
szcax......you're right.....all of the months except Feb.
Actually, if szcax is right, the question is wrong. If 11 months have 30 days, February does not have 28 or 29 days - February always has 28 days (and sometimes 29).
I realize that this is supposed to be a trick question but it's an internally inconsistent trick question.
I forgot my sig.
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| 12 JAN 2003 at 11:41am |
MichalNGrand Inquisitor
Posts : 7058
Joined: 14 SEP 2003
Status : Online | Originally Posted By InlandAZ (12 JAN 2003 2:12am)
This is a common test we give self procliamed "ace" programmers to make them feel humble... But, it can be done...
That's a nifty question... let's see if I can solve that.
Okay, we can't use binary search because we don't know if the odd ball is lighter or heavier and I assume that it looks the same as the others
But looking at the problem from the information theory standpoint, we have 24 possible outcomes (one of 12 balls, heavier or lighter) and three weighings with three possible results each (heavier, lighter, same) give us 27 possible combinations. So it might be solvable.
We could split the 12 balls into three sets of four. I will call them ABCD, EFGH and IJKL. First we weigh ABCD and EFGH. There are two possibilities:
1) ABCD and EFGH weigh the same. In that case the odd ball is one of IJKL and we've just got ourselves 8 "reference" balls. Second time we weigh ABC and IJK. Again two possibilities:
1a) ABC and IJK weigh the same. In that case the odd ball is L and in third weighing we determine if it's heavier or lighter by comparing it to any other ball.
1b) ABC and IJK don't weigh the same. At this point we'll know if the odd ball is heavier or lighter, we just need to find out which one it is. Let's weigh I and J - either one of them will be heavier/lighter and then it's the odd ball or they'll weigh the same in which case K is the odd one.
2) ABCD and EFGH do not weigh the same. We have no idea which is the odd ball but once we find out which one it is, we'll know if it's heavier or lighter. We also have 4 reference balls (IJKL). Let's try weighing ABE vs. CFI. Again two possibilities.
2a) ABE weigh the same as CFI. The odd ball must be D, G or H. So we'll weigh G against H. If they're the same, D is the odd ball, if not, we'll determine the odd ball by looking at the first weighing (if EFGH was heavier in first weighing, the heavier is the odd ball and vice versa).
2b) ABE do not weigh the same as CFI. This is where it gets tricky. E and C switched sides, so if ABC was heavier but ABE isn't, either E or C is the odd ball. We can weigh one of them against a "reference" ball and find out. In the other case A, B or F is the odd ball. We should weigh A against B and find out which. From the first weighing we will know if it's heavier or lighter.
Whew, I think that's it... I may have missed something, I'm no ace programmer
I forgot my sig.
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| 12 JAN 2003 at 1:19pm |
ElfstoneGuild Master
Posts : 5892
Joined: 4 NOV 2002
Status : Online | Pssst...I tell you something...come closer...
Michal is cheating!!!
The solution to Inland's problem can be found on the very same page he found the alternative wording to Rael's brain teaser.
And it's at the very top on that page!
Sorry. :-X
[b]playing[/b]: Destination Treasure Island (done in two sittings, but it's nice), Syberia (ho-hum), Dracula: Last Sanctuary (on hold)&&[b]reading[/b]: even more study papers&&[b]listening to[/b]: [url=http://www.last.fm/user/Brax82/]this and that[/url], plus [url=http://www.musicovery.com/]Musicovery[/url]&&[b]TV favorites[/b]: (currently) Pushing Daisies, Chuck, Journeyman (cancelled! grrr...), Heroes&& all-time) 24, Stargate SG1, X-Files, Lost, House
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| 12 JAN 2003 at 5:45pm |
InlandAZGuild Master
Posts : 5586
Joined: 4 MAY 2007
Status : Offline | Michal is cheating!!!
I wouldn’t think MichalN would be cheating - and to be honest I wasn't aware the answer was posted (although it doesn't surprise me...)
To MichalN's credit he does have the basic concept - most people ignore the fact that there are a set of "Known" samples, in his words "reference balls"...
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| 12 JAN 2003 at 10:01pm |
MichalNGrand Inquisitor
Posts : 7058
Joined: 14 SEP 2003
Status : Online | Originally Posted By Elfstone (12 JAN 2003 1:19pm)
The solution to Inland's problem can be found on the very same page he found the alternative wording to Rael's brain teaser.
And it's at the very top on that page!
Aghhhh! Why didn't someone tell me earlier! I spent about two hours figuring out the solution >
Is mine at least the same as theirs? Because I honestly did not look at it and I don't even know if my solution is correct - I guess if it's not, that's a good proof I wasn't cheating
I forgot my sig.
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| 12 JAN 2003 at 10:09pm |
MichalNGrand Inquisitor
Posts : 7058
Joined: 14 SEP 2003
Status : Online | Originally Posted By InlandAZ (12 JAN 2003 5:44pm)
I wouldn't think MichalN would be cheating - and to be honest I wasn't aware the answer was posted
I can never prove that I wasn't cheating so it's up to you to determine whether I would be wasting my time pretending to look clever
To MichalN's credit he does have the basic concept - most people ignore the fact that there are a set of "Known" samples, in his words "reference balls"...
Right - and the "reference balls" (as I called them) will be known after the first weighing. The other "trick" is that results of previous weighings can be used later on. And the last trick is setting up the weighings so that the results can always be lighter/heavier/equal. That way you can "expand" the amount of information that can be squeezed out of each weighing. In other words, having only "known good" ball(s) on one side is no good because it wastes an opportinuty for acquiring more information.
I still don't know if my solution is correct though, it was 4am when I wrote it so I'd be kinda surprised if it was right
I forgot my sig.
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| 13 JAN 2003 at 8:32pm |
ElfstoneGuild Master
Posts : 5892
Joined: 4 NOV 2002
Status : Online | Sorry Michal, I was just teasing you!
I don't even know if your solutions is correct. It doesn't seem it's complete.
[b]playing[/b]: Destination Treasure Island (done in two sittings, but it's nice), Syberia (ho-hum), Dracula: Last Sanctuary (on hold)&&[b]reading[/b]: even more study papers&&[b]listening to[/b]: [url=http://www.last.fm/user/Brax82/]this and that[/url], plus [url=http://www.musicovery.com/]Musicovery[/url]&&[b]TV favorites[/b]: (currently) Pushing Daisies, Chuck, Journeyman (cancelled! grrr...), Heroes&& all-time) 24, Stargate SG1, X-Files, Lost, House
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| 13 JAN 2003 at 10:07pm |
MichalNGrand Inquisitor
Posts : 7058
Joined: 14 SEP 2003
Status : Online | Originally Posted By Elfstone (13 JAN 2003 8:32pm)
Sorry Michal, I was just teasing you!
Sometimes it's hard to tell... and the solution really is on that web page. I still haven't looked at it though.
I don't even know if your solutions is correct. It doesn't seem it's complete.
Why don't you come up with a better solution then
I forgot my sig.
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| 13 JAN 2003 at 10:11pm |
ElfstoneGuild Master
Posts : 5892
Joined: 4 NOV 2002
Status : Online | Originally Posted By MichalN (13 JAN 2003 10:07pm)
Why don't you come up with a better solution then
Wouldn't be wise, because I already know how to solve it...I've consulted the solution when I tried to solve it.
[b]playing[/b]: Destination Treasure Island (done in two sittings, but it's nice), Syberia (ho-hum), Dracula: Last Sanctuary (on hold)&&[b]reading[/b]: even more study papers&&[b]listening to[/b]: [url=http://www.last.fm/user/Brax82/]this and that[/url], plus [url=http://www.musicovery.com/]Musicovery[/url]&&[b]TV favorites[/b]: (currently) Pushing Daisies, Chuck, Journeyman (cancelled! grrr...), Heroes&& all-time) 24, Stargate SG1, X-Files, Lost, House
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| 15 JAN 2003 at 3:34am |
MichalNGrand Inquisitor
Posts : 7058
Joined: 14 SEP 2003
Status : Online | So, what is the right solution InlandAZ?
And where are more puzzles?
I forgot my sig.
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| 16 JAN 2003 at 12:27am |
InlandAZGuild Master
Posts : 5586
Joined: 4 MAY 2007
Status : Offline | Originally Posted By MichalN (15 JAN 2003 3:34am)
So, what is the right solution InlandAZ?
And where are more puzzles?
I've been this thread at least 5 times today - and work keeps interrupting me... This one always requires me to think - Hey, somethings burning in here I'll run through this again later, but this should work.
Your assumption to break the sets up into 3 groups of 4 is correct. I also think you were on to the right track because you realized the value of the reference set.
Here is one solution. I am aware of at least one other.
[size=16]1st Weighing
Weigh the following: 1,2,3,4 vs 5,6,7,8 (Place the remaining balls off to the side).
If Not Equal see Solution When 1st Weighing is Not Equal, otherwise see Solution When 1st Weighing is Equal.
[size=16]Solution When 1st Weighing is Not Equal.
Note the direction the scale tilts. You're going to use the information later.
[tt]Remove 2 of the balls (one even numbered the other odd) from the "Right Hand Side of the Scale". Redistribute the remaining balls so that the odd numbers are on one side and the even numbers on the other.
Use this as a visual reference below: 2nd Weighing: 1,3,5 vs 2,4,6 (7 and 8 are out)
[/tt]
2nd Weighing Results and Final Test[tt]
Possibility 1 - Equal
Weigh 7 & 8 (or which ever 2 you removed). What you want to find here is the ball that travels in the same direction as the "Right Hand Side of the Scale" did in the first weighing... i.e. It either went up or down - If it went up, the ball that goes up is odd (and lighter), otherwise... it's odd and heavier...
Possibility 2 - Not equal (same direction of tilt)...
Weigh 1 and 3, if they're equal then 6 is the odd ball. It's also heavier if the "Right Hand Side of the Scale" went down in the first test... otherwise... it's lighter...
If 1 and 3 are not equal look for the ball that follows the same direction as the "Left Hand side of the Scale" did in the first test. Up is lighter, down is heavier.
Possibility 3 - Not equal (opposite direction of tilt)...
Weigh 2 and 4, if they're even then 5 is the odd ball... If the "Left Hand Side of the Scale" went down in the first test it is heavier... otherwise... it's odd and lighter...
If 2 and 4 are not even - then the ball that follows the same direction as the "Right Hand Side of the Scale" is different. Up is lighter, Down is heavier.
[/tt]
[size=16]Results When 1st Weighing is Equal
[tt]Pick a ball, any ball, from the excluded set (numbered 9 through 12)... Lets use 12 in this example, but it's not important which one you choose.
Keep a single "reference ball" from the first set weighed (numbered 1 through 8.) - I'll use 8...
Use this as a visual reference below: Second Weighing is: 8, 9 vs 10, 11 (12 is out)
[/tt]
2nd Weighing Results and Final Tests
[tt]
Possibility 1 - Equal
Weigh any ball and 12 - If 12 goes up it's lighter, otherwise it heaver. and... it's definately the odd ball.
Possibility 2 - Not Equal
Weigh 10 and 11 - If equal then 9 is odd. If the "Right Hand Side of the Scale" went down it is heavier... Otherwise it's lighter.
If 10 and 11 are not equal then the ball that travels in the same direction as the "Right Hand Side of the Scale" in the previous weighing is odd.
[/tt]
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| 16 JAN 2003 at 1:23am |
MichalNGrand Inquisitor
Posts : 7058
Joined: 14 SEP 2003
Status : Online | Originally Posted By InlandAZ (16 JAN 2003 12:27am)
Here is one solution. I am aware of at least one other.
This sounds very very similar to my solution, but the wording is somewhat different (numbers instead of letters etc.) so it's not so easy to tell
I forgot my sig.
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| 16 JAN 2003 at 1:42am |
InlandAZGuild Master
Posts : 5586
Joined: 4 MAY 2007
Status : Offline | Originally Posted By MichalN (16 JAN 2003 1:22am)
This sounds very very similar to my solution, but the wording is somewhat different (numbers instead of letters etc.) so it's not so easy to tell
Yeah, I know - I'll go back through your response and test it - Unfortunately, this is the way I solved it (many years ago).. It's hard to teach an old dog new tricks - so to speak...
And a little FYI I'm Dyslexic (up the you know what...) I hate working with letters... For what ever reason... numbers (especially 0's and 1's) don't have the same affect on me...
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| 16 JAN 2003 at 1:43am |
InlandAZGuild Master
Posts : 5586
Joined: 4 MAY 2007
Status : Offline | By the way - If that's the first time you've ever seen the puzzle.. You did a hell of a job. I know many that never get it right.
Good job!
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