HDTenEightyP/NetNews huggingface dataset:
From: bmoore@sunfish.austin.ibm.com (Bryan Moore)
Newsgroups: rec.puzzles
Subject: Re: ARRGGHHHH
Date: 26 Jan 93 20:52:05 GMT
Organization: IBM, Austin


From: karr@cs.cornell.edu (David Karr)
>In article <C1GuHw.zuF@austin.ibm.com> bmoore@sunfish.austin.ibm.com (Bryan Moore) writes:
>>[...]
>>Back to the dice... Roll two dice 100 times. Get 100 pieces of paper and
>>write the results of the first die on one side and write the results
>>of the second die on the other side of the piece of paper. Put all the
>>pieces of paper in a hat. Now pick a piece of paper out of the hat.
>>You see a six on the piece of paper, what is the probability that the
>>other side has a six? IT IS 1/11!!!!!!! 

>No, it's 1/6.  Have you tried it?  Get someone who really understands
>probability to explain it to you.  Or you can simulate it easily on a
>computer, but remember, a paper with two 6's can be selected in two
>different ways but a paper with only one 6 can be selected in only one
>way (if the first side you look at is the other side you have to
>discard the event).

>-- David Karr (karr@cs.cornell.edu)

Ooops...you are right about the dice.
And after pondering this whole problem for a 
while I've come to the conclusion that the answer to the original
problem can be either 1/3 or 1/2 depending on how you word and
interpret the question. 

I like the way Martin Gardner worded the problem in one of his books.

There are two owls in a cage. One of them is male. What is the 
probability they are both male? Now, the way this is worded, I don't
see how you can argue for an answer of 1/2 over 1/3. 

Oh, and by the way David, do you *really* understand probability? :-)

-Bryan
-- 
_/_/
_/_/_/       bmoore%sunfish.ibm.com@ibmpa.austin.ibm.com
_/_/_/_/
_/_/_/_/_/
From: t91matfa@odalix.ida.liu.se (Mattias Fagerlund)
Newsgroups: rec.puzzles
Subject: A puzzle?
Date: 21 Jan 93 11:54:27 GMT
Organization: CIS Dept, Univ of Linkoping, Sweden

Well, lets see if this puzzle fits you.

The solution seems me totally logical, but not every body might think so.
You may ask me as many questions as you wish, but mail them to my person, 
so you don't spoil it for the others.
Questions will be answered with yes, no and irrelevant (most are).

A man walks into a saloon and asks the bartender for a glass of water.
The bartender, saying nothing, pulls out a shot-gun and points it at the man.
-Thank you, the man says and leaves the bar.

Question: 
  What really happend? Why did the man say thank you (his goal WAS actually 
 achived) and leave?

	-Mattias Fagerlund 
 	t91matfa@und.ida.liu.se
Newsgroups: rec.puzzles
From: karr@cs.cornell.edu (David Karr)
Subject: Re: Are you sure? NO - flame-resistant clothing ON <SPOILER>
Organization: Cornell Univ. CS Dept, Ithaca NY 14853
Date: Thu, 28 Jan 1993 19:59:15 GMT

In article <93027.155827RVESTERM@vma.cc.nd.edu> <RVESTERM@vma.cc.nd.edu> writes:
>[...] let's dissect the question: "i have two children.
>at least one is a daughter. what's the chance that the other is a daughter?"
>is the same as "what is the chance that both of my children are female, given
>that at least one is female?"

Maybe.

I have two children, at least one is a daughter.  What's the chance
that the other is a daughter?

My mother has two children, at least one is a son.  What's the chance
that the other is a son?

My cousin Charlotte has two children, at least one is a son.  What's
the chance that the other is a son?

Is the answer 1/3 in all cases?  Can you reconcile that with the fact
that the first question is about daughters and the others are about
sons?

In any case, none of this has anything to do with meeting any of these
offspring in the street, which is a different sampling procedure
altogether.

-- David Karr (karr@cs.cornell.edu)

Newsgroups: rec.puzzles
From: thompson@spot.Colorado.EDU (THOMPSON  BENJAMIN RHINELANDER)
Subject: Re: Need puzzle help: eye colour enigma
Organization: University of Colorado, Boulder
Date: Tue, 26 Jan 1993 05:54:27 GMT

In article <1993Jan19.035603.19176@CSD-NewsHost.Stanford.EDU> bhayes@Xenon.Stanford.EDU (Barry Hayes) writes:
>In article <1993Jan19.143459.13275@waikato.ac.nz> deryl@waikato.ac.nz writes:
>> [FAQ deleted]
>
>Once the guru has spoken, is there anything he or anyone else can say
>or do that will stop the chain of events?
>

	If one blue-eyed person immidiately shouts "I see a blue-eyed
person too!" doesn't that save everyone?



-- 
Do not be lulled by my present condition,
Psmith. There are only 35 of you.
From: Bob_Hearn@qm.claris.com (Robert Hearn)
Newsgroups: rec.puzzles
Subject: Re: RAAARRGGHH!!!! not again!
Date: 28 Jan 93 02:01:25 GMT
Followup-To: rec.puzzles
Organization: Spartacus Software

In article <1993Jan26.155709.25082@cs.cornell.edu>, karr@cs.cornell.edu
(David Karr) wrote:
> 
> In article <C1GuHw.zuF@austin.ibm.com> bmoore@sunfish.austin.ibm.com (Bryan Moore) writes:
> >[...]
> >Back to the dice... Roll two dice 100 times. Get 100 pieces of paper and
> >write the results of the first die on one side and write the results
> >of the second die on the other side of the piece of paper. Put all the
> >pieces of paper in a hat. Now pick a piece of paper out of the hat.
> >You see a six on the piece of paper, what is the probability that the
> >other side has a six? IT IS 1/11!!!!!!! 
> 
> No, it's 1/6.  Have you tried it?  Get someone who really understands
> probability to explain it to you.  Or you can simulate it easily on a
> computer, but remember, a paper with two 6's can be selected in two
> different ways but a paper with only one 6 can be selected in only one
> way (if the first side you look at is the other side you have to
> discard the event).
> 
> -- David Karr (karr@cs.cornell.edu)


Well, you're right, but when you ask the problem the CORRECT way, that
is, don't mention meeting someone on the street, then the answer is
1/3, not 1/2.  If there were a club for every family in the US that
had two children at least one of which was a girl, and everyone
qualified joined, then only 1/3 of the member families would have the
other daughter also a girl.

Or, in terms of the paper hat, you have to look at both sides.  If EITHER
side is a six, then the probability that the OTHER side is a six is
1/11.  It's the unintuitiveness of the way you're given the information
that obscures the answer.

Bob Hearn
Spartacus Software

Opinions expressed here are those of my empolyer, since that's me.
From: chris@questrel.com (Chris Cole)
Newsgroups: rec.puzzles
Subject: Re: 27+2=30
Date: 27 Jan 93 18:05:21 GMT
Organization: Questrel, Inc.

In article <1k2sfkINN9pf@sipi.usc.edu> haddadi@sipi.usc.edu (Navid Haddadi) writes:
>Here is a very old puzzle:
>Three men rent a room for $30. The inn keeper decides that he has
>over charged them and gives the bellboy $5 to give back to the men.
>The bellboy decides to keep $2 and give each man $1. 
>So, each man has paid $9 (3x9=27) plus the $2 that the boy kept.
>Hence, 27+2=30.
>
>It is actually more funny than silly!


This question is in the rec.puzzles Archive.

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From the Archive, the answer is:
********
logic/29.s
********
Each person paid $9, totalling $27.  The manager has $25 and the bellboy $2.
The bellboy's $2 should be added to the manager's $25 or subtracted from
the tenants' $27, not added to the tenants' $27.
Newsgroups: rec.puzzles
From: ags@seaman.cc.purdue.edu (Dave Seaman)
Subject: Re: "map" of USA
Organization: Purdue University
Date: Mon, 25 Jan 1993 04:32:14 GMT

In article <1993Jan24.154526.24491@zip.eecs.umich.edu> kanad@quip.eecs.umich.edu (Kanad Chakraborty) writes:
>In article <19692.2b617217@ecs.umass.edu> padmanab@ecs.umass.edu writes:
>>Suppose you have two maps of USA of different 
>>scales. Now you place the smaller map inside 
>>the bigger map such that it falls completely 
>>within it. 
>
>This is possible only if you don't include Alaska and Hawaii, and
>consider only the continental landmass that lies between Canada and
>Mexico.

Why? Let one map be, say, a mile across, and the other about a foot across. The
second map will probably fit entirely within, say, Nebraska on the large map.

>>Condider each point on the map to be a distinct 
>>city!! 
>>
>>QUESTION: Are there any city/cities on the 
>>smaller map which will coincide with the 
>>city/cities  on the bigger map? If so why? 
>
>Yes, if the larger map can be regarded as a projection of the smaller one
>-- this causes the point of projection to represent the same city in both
>maps. (Assumption : Alaska and Hawaii have not been considered.)

No special assumptions are needed. It does no harm if you decide to place the
small map within Alaska or Hawaii on the large map.

Pick a city a1 on the large map, and find the corresponding city b1 on the
small map. Since the small map lies within the large map, b1 overlies a point
(city) a2 on the large map, which corresponds to a point b2 on the small map.
Continuing the process, we arrive at a sequence of points a1, a2, a3, ... on
the large map, and a corresponding sequence b1, b2, b3, ... on the small map.
It is not hard to show that the sequences converge to a point (city) that
is a fixed point of the mapping. As long as the scales differ, the fixed point
is unique.

--
Dave Seaman
ags@seaman.cc.purdue.edu
From: dik@cwi.nl (Dik T. Winter)
Newsgroups: rec.puzzles
Subject: Re: Cities with an internal border
Date: 26 Jan 93 01:19:27 GMT
Organization: CWI, Amsterdam

In article <C1DzLH.8u7@techbook.com> dant@techbook.com (Dan Tilque) writes:
 > An example is Kansas City MO/KS.  The names must be identical so
 > Laredo/Neuvo Laredo does not count.
This is a bit of a set-back.  There are quite a few cities in Europe that
cross borders, but the name on both ends is different.
 > 
 > So far, I've found about half a dozen in North America (some are fairly
 > small though), but none on other continents.
True, except for Berlin upto a few years ago there are no single-named
examples.  But let's take the spirit rather thanm the letter of the question.
I.e. a single city that straddles borders (rather than two cities that
grow together).  I accept different names if they are only due to political
reasons.  In that case I know of two in Europe:
	Kerkrade(NL) - Herzogenrath(D)
here the border is right in the middle of a fairly important street.  It is
two way both at the German and at the Dutch side, with a one foot high
barrier in between (I presume that will change shortly, though I have no
idea what they will do with southbound traffic on the Dutch side and
northbound traffic on the German side, traffic signs depending on direction?).
	Baarle-Nassau(NL) - Baarle Hertog(B)
A village rather than a city, but one of the strangest cases I know off.
There are houses that straddle the border.  There are people with both
a Belgian and a Dutch mailbox.  Moreover, the Belgian parts are enclaves
within the Netherlands, but within the Belgian parts there are Dutch
enclaves again.  Smugglers paradise when the Dutch-Belgian border was
still important, but that is about 35 years ago.
-- 
dik t. winter, cwi, kruislaan 413, 1098 sj  amsterdam, nederland
home: bovenover 215, 1025 jn  amsterdam, nederland; e-mail: dik@cwi.nl
From: dik@cwi.nl (Dik T. Winter)
Newsgroups: rec.puzzles
Subject: Re: RAAARRGGHH!!!! not again!
Date: 28 Jan 93 00:04:42 GMT
Organization: CWI, Amsterdam

In article <C1GuHw.zuF@austin.ibm.com> bmoore@sunfish.austin.ibm.com (Bryan Moore) writes:
 > Ralph, you are dead wrong.
No, strange enough, Ralph's answer is right.
The question was: you meet one girl, what are the chances of the other also
being a girl.  This question has a different solution than when one of the
parents tells you that there is one girl.

 >                                            We're saying that both children
 > have been born and you see one of them on the street, you don't know which
 > child). You see a girl, what's the probability the other is a girl. 
Yup, that is the question.
 > 
 > Back to the dice... Roll two dice 100 times. Get 100 pieces of paper and
 > write the results of the first die on one side and write the results
 > of the second die on the other side of the piece of paper. Put all the
 > pieces of paper in a hat. Now pick a piece of paper out of the hat.
 > You see a six on the piece of paper, what is the probability that the
 > other side has a six? IT IS 1/11!!!!!!! 
But this is the answer to the other question!  (You throw two dice, one of
them shows a 6, what is the probability that the other also shows a 6.)

The correct analogy is: you throw two dice, the first one you see shows a
6, what is the probability that the other one shows a 6.

The other question can also be put as the next analogy: you throw two dice,
the first one you see shows a 6, and/or the second one you see shows a 6,
what is the probability that both show a 6.
-- 
dik t. winter, cwi, kruislaan 413, 1098 sj  amsterdam, nederland
home: bovenover 215, 1025 jn  amsterdam, nederland; e-mail: dik@cwi.nl
From: chris@questrel.com (Chris Cole)
Newsgroups: rec.puzzles
Subject: Re: A puzzle?
Date: 22 Jan 93 19:05:35 GMT
Organization: Questrel, Inc.

In article <1993Jan21.115427.29195@ida.liu.se> t91matfa@odalix.ida.liu.se (Mattias Fagerlund) writes:
>Well, lets see if this puzzle fits you.
>
>The solution seems me totally logical, but not every body might think so.
>You may ask me as many questions as you wish, but mail them to my person, 
>so you don't spoil it for the others.
>Questions will be answered with yes, no and irrelevant (most are).
>
>A man walks into a saloon and asks the bartender for a glass of water.
>The bartender, saying nothing, pulls out a shot-gun and points it at the man.
>-Thank you, the man says and leaves the bar.
>
>Question: 
>  What really happend? Why did the man say thank you (his goal WAS actually 
> achived) and leave?
>
This is what we call a "situation puzzle."  A very long list of such
puzzles is in the rec.puzzles Archive, under the name "situation.puzzles."

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From: uurtamos@helium.gas.uug.arizona.edu (stephen j uurtamo )
Newsgroups: rec.puzzles
Subject: Re: Irrational numbers
Date: 27 Jan 93 17:34:25 GMT
Organization: UofA Mathematics Department


 i(pi)
e     = -1.


ppppphhhbbbt.


steve
Newsgroups: rec.puzzles
From: karr@cs.cornell.edu (David Karr)
Subject: Re: hoosier-cash-lotto-inspired puzzle.
Organization: Cornell Univ. CS Dept, Ithaca NY 14853
Date: Mon, 25 Jan 1993 14:42:08 GMT

In article <93024.165953RVESTERM@vma.cc.nd.edu> <RVESTERM@vma.cc.nd.edu> writes:
>you see the results of a lottery drawing: n numbers, i1, i2, ..., in.
>what is the chance that the highest number possible in the lottery is
>k?

This seems more of a statistics question than a probability question.
You have a probability distribution with one parameter (k) and you
want to estimate the value of k from a set of actual data, using some
formula.  But you need to make some kind of assumption about the
distribution of k itself in order to ask your question.  Suppose your
formula gives k=29.  I would guess that k=30 is much more likely to be
the parameter for a real-life lottery in that case.

> also, what is the chance that
>there is no k such that k is the highest number possible?

I.e. every positive integer has a non-zero probability of being selected
by the first ball?  Then surely the distribution of this variable is not
uniform, unlike every lottery I know of.

>bob vesterman.

-- David Karr (karr@cs.cornell.edu)


Newsgroups: rec.puzzles
From: serdar@fawlty8.eng.monash.edu.au (Serdar Boztas)
Subject: Re: Cities with an internal border
Organization: Monash University, Melb., Australia.
Date: Tue, 26 Jan 1993 23:13:54 GMT

Nicosia, the capital of Cyprus is divided by the green line
between the Turkish and Greek parts of Cyprus. This is not
an international border per se, rather a cease fire line from
1974.

Serdar

PS: No flames about whether the border should be there or not,
I am just stating a fact, go to soc.culture.turkish/greek if
you want to argue.
 
-- 
serdar boztas			serdar@fawlty8.eng.monash.edu.au
	    '
sevdalarda olsun, ilkyaz olumlerinde olsun/ gecit vermeyen akarsu olmaz
gu"lu"n kendini islemek icin/ ciragi ya da ustasi yoktur  --hilmi yavuz
From: cooper@cbnewsg.cb.att.com (Ralph 'Hairy' Moonen)
Newsgroups: rec.puzzles
Subject: Re: RAAARRGGHH!!!! not again!
Date: 27 Jan 93 10:10:40 GMT
Organization: AT&T

In article <C1GuHw.zuF@austin.ibm.com>, bmoore@sunfish.austin.ibm.com (Bryan Moore) writes:
> >You are throwing 2 consecutive dice. The first one turns up a six. What is
> >the chance of the second also being a six. It's easy to see that because dice
> >have no memory, the chance is also 1/6. Now, following your line of reasoning,
> >there are 36 different ways to throw the dice. Because 1 six already has
> >been thrown this leaves 11 combinations, one of which is a double six.
> >So, according to you, you only have 1/11 chance of throwing a second six.
> >Clearly this is dead wrong.
> 
> >--Ralph
> Ralph, you are dead wrong. Let's look closer at your dice analogy to see why.
> To compare the dice problem to the boy/girl problem, you need to toss the
> dice a bunch of times and write the results down and put them in a hat.
> This is because the two children are already born, and we're not saying
> that if a woman has given birth to a girl, and is pregnant, what is the
> probability that the next child is a girl. We're saying that both children
> have been born and you see one of them on the street, you don't know which
> child). You see a girl, what's the probability the other is a girl. 
> 
> Back to the dice... Roll two dice 100 times. Get 100 pieces of paper and
> write the results of the first die on one side and write the results
> of the second die on the other side of the piece of paper. Put all the
> pieces of paper in a hat. Now pick a piece of paper out of the hat.
> You see a six on the piece of paper, what is the probability that the
> other side has a six? IT IS 1/11!!!!!!! 

The way you put it, you are still wrong. You are *given* the *fact* that
1 dice is a six. Your p[iece of paper has a six on 1 side. There are
left the combinations of 6-1, 6-2, 6-3, 6-4, 6-5, and 6-6. No other ones
possible, because you allready *know* there's 1 six. So the chance of
the other side being a six is 1/6. You make the mistake of making
a difference on which side of the paper the six is on. When you pick
a paper, and it has a 2 on it, you will also have to check the other
side to see if there's a six on it. The combination of 6-2 and 2-6 are
identical, because it is given that one of the two is six. 

Let's bring this back to the boy/girl problem. 
The (wrong) reasoning is that the possibilities are BG GB GG and BB.
But if you includeboth GB and BG, you should also include an extra
GG and BB, if you want to take birth order into account. Chances stay 
50/50.

This whole thing can be found in any statistical textbook, and is 
easy to understand when you realise that dice do not communicate. They
have no way of telling the other dice "Hey, I'm a six". They are 
independant entities.

--Ralph
Newsgroups: rec.puzzles
From: karr@cs.cornell.edu (David Karr)
Subject: Re: No subject
Organization: Cornell Univ. CS Dept, Ithaca NY 14853
Date: Tue, 26 Jan 1993 16:14:28 GMT

In article <1993Jan26.143630.1@skaro.demon.co.uk> richard@skaro.demon.co.uk (Richard Develyn) writes:
>
>You and two other people (call them B and C) are locked, in separate 
>cells, in a prison.  You are told that two of you are to be executed. 
>So you calculate your chances of survival to be 1 in 3.
>
>The gaoler wanders round and you say to him that, since clearly at 
>least one of the two other chaps is going to die, he wouldn't be 
>giving anything away by telling you which one. He does - say B. Now, 
>amazingly, you calculate your chances of survival as 1 in 2 since it 
>is clear that either C or you will be the other victim.

Aaargh--it's Monty Hall all over again.

Cajoling the gaoler into giving you information about the other
prisoners doesn't tell you anything about yourself in this case.
Your odds of survival are still 1/3.  The odds of C's survival
(based on what you now know) have risen to 2/3, however.

So if the warden comes around and says he will not tell you who
is to be executed but he will let you change places with one of
the other prisoners if you like (and so to suffer whatever fate
had been decided for them), it is to your advantage to take
C's place.

-- David Karr (karr@cs.cornell.edu)

Newsgroups: rec.puzzles
From: gupta@iiasa.ac.at (Sujata GUPTA)
Subject: 1
Organization: IIASA, Laxenburg, Austria
X-Newsreader: TIN [version 1.1 PL6]
Date: Thu, 21 Jan 1993 11:16:31 GMT

Why is everyone such a pessimist? in the blue eyed and brown eyed puzzle
I say no one will kill himself/herself because they don't know the colour
of their eyes and why should people start telling each other after the comment
from the guru.
Newsgroups: rec.puzzles,sci.math