HDTenEightyP/NetNews huggingface dataset:
From: imc@comlab.ox.ac.uk (Ian Collier)
Newsgroups: rec.puzzles
Subject: Re: Height of a building
Date: 9 Oct 92 16:09:10 GMT
Organization: Oxford University Computing Laboratory, UK
X-Local-Date: Friday, 9th October 1992 at 5:08pm BST
Originator: imc@msc3.comlab

In article <1992Oct7.192415.217922@ns1.cc.lehigh.edu>, dsbb@ns1.cc.lehigh.edu (D. SPENCER BEECHER) wrote:
>How would you accurately measure the height of a ten or twelve
>story building?

>Tools at your disposal include a cigarette lighter, a plastic
[etc]

>It is a dark night (no moon), and the solution is required
>before morning.

Why so dark?  Can you see the building at all? If not, you are going to have
trouble finding your way into it in order to measure it, aren't you? ;-)

Assuming you can see the building, use the 12m plastic tube as a large ruler
and stand exactly 48m away from the building.  Hold the 12in ruler in front
of your face, close one eye and stretch some string between your (open) eye
and the ruler.  Move the ruler away/towards you, keeping the string taut and
approximately level, until the ruler is exactly the same size as the
bulding.  With the ruler, measure the length of the string between the ruler
and your eye.  I expect the answer will be in the region of 16 inches for a
12 storey building.  Divide 576 by that answer, and you have the height of
the building in meters.  You will be within the required 1m tolerance if you
measure the 48m to within 0.3m and the string to within 0.3 inches.

You did say that the plastic tube is 12 meters long.  I hope you meant that
it is *exactly* 12 meters long.  Note that I used the ruler only to measure
inches; some other answers have required the imperial ruler to be used to
measure in meters.

Ian Collier
Ian.Collier@prg.ox.ac.uk | imc@ecs.ox.ac.uk
Date: Monday, 12 Oct 1992 22:51:33 EST
From: <RVESTERM@vma.cc.nd.edu>
Newsgroups: rec.puzzles
Subject: blue eyes, brown eyes revisited.

what is all this talk about the blue-eyed natives dying on the 300th day?

the natives, being totally logical, take a clue from mr. spock: "the needs
of the many outweigh the needs of the few, or the one."

the natives get together as soon as the visitor ships off, and everyone
is assigned an integer from 1 to 1000 (with everyone getting a different
integer).

number one gets up on stage.  he asks, "what color eyes do i have?"
the masses tell him, truthfully.  if he has blue eyes, everybody goes home,
and he kills himself that night.  if he has brown eyes, he sits down, and
number two gets up on stage.  he asks [repeat the process]....

this process is repeated until a blue-eye is found.

this breaks the induction.  exactly one blue-eye will kill himself, no
matter how many there are.  this is no loss if there is only one blue-eye,
and it is certainly a gain if there are more than one blue-eye.

to see that it breaks the induction, consider the case "there is one
blue-eyed native."  he finds out he's blue-eyed, since he knows no one
else is.  when his turn on stage comes, he gets up and asks, "what color
eyes do i have," even though he knows the answer.  they tell him, "blue,"
and that night he kills himself.

now let's say that i am a native, and i see exactly one blue-eye.  his turn
on stage is before mine.  he gets up, asks "what color eyes do i have,"
we tell him "blue," and he goes home and kills himself that night.
I NO LONGER KNOW THAT THERE IS A BLUE-EYED PERSON ON THE ISLAND.

if i am a native who sees exactly two blue-eyes, one of them dies.  i know
that there is a blue-eyed person on the island, but I NO LONGER KNOW THAT
HE KNOWS THAT THERE IS A BLUE-EYED PERSON ON THE ISLAND.

if i am a native who sees exactly three blue-eyes, one of them dies.  i
know that there are at least two blue-eyed people left.  i know that
everyone knows that there is at least one blue-eyed person left.  but I NO
LONGER KNOW THAT EVERYONE KNOWS THAT EVERYONE KNOWS THAT THERE IS A
BLUE-EYED PERSON ON THE ISLAND.

proceed in the obvious manner, up to "I NO LONGER KNOW THAT EVERYONE KNOWS
THAT ... THAT EVERYONE KNOWS THAT THERE IS A BLUE-EYED PERSON ON THE ISLAND."

we arrive at the same situation that existed before the traveller arrived,
minus one blue-eyed person.

it may be heartless, but it's logical.
From: radcliff@csd4.csd.uwm.edu (David G Radcliffe)
Newsgroups: rec.puzzles
Subject: Re: teez brainbuster
Date: 12 Oct 1992 04:34:22 GMT
Organization: UW-Milwaukee Math Department
NNTP-Posting-Host: 129.89.7.4

Here's another way of thinking of the puzzle.
You start with a string of O's, R's, and B's.
You are allowed to do the following transformations:

  1.  BOR ---> OBR
  2.  BOR ---> BRO
  3.  BRO ---> ORB 
  4.  OBR ---> RBO

The problem is then to transform (B^n)O(R^n) to (R^n)O(B^n).

I think a proof by induction will work here, but I haven't worked it out.

--
David Radcliffe                                
radcliff@csd4.csd.uwm.edu
From: mk0e@ns1.cc.lehigh.edu (MAHEENDRA BABURAO KASMALKAR)
Newsgroups: rec.puzzles
Subject: Re: GRY
Date: 9 Oct 92 00:17:42 GMT
Organization: Lehigh University

In article <1auk07INN7f6@usenet.INS.CWRU.Edu>, cb971@cleveland.Freenet.Edu (Mari
on L. Rappa) writes:
>
>   Are there more than three words in the English language
>that end in gry?
>--
>
>Muntz Rappa
>cb971@cleveland.Freenet.Edu
>

I know just two : angry and hungry. I have been looking for the third since a
friend of mine asked me this question. Do you know the third?

Maheendra
-- 
------------------------------------------------------------------
!  My life in US :            !      Maheendra Kasmalkar         !
!                             !      mk0e@lehigh.edu             !
!  Apartment , Department     !      mk0e@ns1.cc.lehigh.edu      !
!  Advisor and Budweiser      !      (215)-758-8081              !
------------------------------------------------------------------
Newsgroups: rec.puzzles
From: m_reymond@zeus.dev.macsch.com (Mike Reymond)
Subject: VCR Plus Codes
Reply-To: m_reymond@macsch.com
Organization: MacNeal-Schwendler Corporation
Date: Mon, 12 Oct 92 15:46:19 GMT


I just got a VCR Plus device (@Fry's in LA for $28.88) and think it's the greatest thing since sliced bread.  No, I am not VCR illiterate. It's just that I have an old VCR which does not have on-screen programming. 

Has anyone out there figgered out how the VCR Plus codes are derived?  
My inquiry is purely academic. I don't intend to invent my own device.
I've tried to determine if there is a consistent pattern, but have found none.
I suspect there is some sort of encryption. I have also noticed that prime time 
shows on channels 2-13 have codes with the fewest digits.


If this has already been answerd in a FAQ, let me know.
If this is the wrong group for this I apologize and point me in the right direction.
From: arromdee@jyusenkyou.cs.jhu.edu (Ken Arromdee)
Newsgroups: rec.puzzles
Subject: Re: Height of a building
Date: 8 Oct 92 05:50:33 GMT
Organization: Johns Hopkins University CS Dept.

In article <1992Oct7.192415.217922@ns1.cc.lehigh.edu> dsbb@ns1.cc.lehigh.edu (D. SPENCER BEECHER) writes:
>How would you accurately measure the height of a ten or twelve
>story building?
>Tools at your disposal include ...
>a goldfish in a six inch (diameter) round goldfish bowl.

Make a pendulum using the string and one of the heavier objects.  Then drop
an object off the top of the building and use the pendulum to time how long
it takes before you hear the crash.

To calibrate the pendulum, you can use the wristwatch, and compensate for the
crude time resolution by taking, say, 100 pendulum cycles and dividing the
elapsed time by 100.
--
"the bogosity in a field equals the bogosity imported from related areas, plus
the bogosity generated internally, minus the bogosity expelled or otherwise
disposed of."  -- K. Eric Drexler

Ken Arromdee (UUCP: ....!jhunix!arromdee; BITNET: arromdee@jhuvm;
     INTERNET: arromdee@jyusenkyou.cs.jhu.edu)
From: dsbb@ns1.cc.lehigh.edu (D. SPENCER BEECHER)
Newsgroups: rec.puzzles
Subject: Height of a building
Date: 7 Oct 92 19:24:15 GMT
Organization: Lehigh University

How would you accurately measure the height of a ten or twelve
story building?

Tools at your disposal include a cigarette lighter, a plastic
ruler (12 inches, no metric calibration), a cheap wristwatch
(analog, no second hand), five thumb tacks, an altimeter that
reads kilometers plus or minus 1%, twelve meters of acrylic
plastic tubing (clear, rigid, one half inch diameter) with a
rubber stopper for each end, a large green wax marker (jumbo
crayon), fourteen empty beer cans (aluminum), three pencils,
eight marbles (clear glass, 12.7mm diameter), a thermometer
(0-100 degrees C), four feet of string (breaks at 60lbs),
twelve sheets of 8 1/2 by 11 inch paper, a pocket knife, and
a goldfish in a six inch (diameter) round goldfish bowl.

It is a dark night (no moon), and the solution is required
before morning.  Assume everything works for the purpose for
which it was designed.  You have access to the building which
has lights, running water, and no windows.  You are able to get
on the roof or outside the building at ground level with whatever
tools are on the list.  There are no lights outside the building.
All the stairway doors are locked (you must use the freight elevator).

Accuracy of plus or minus one meter is required.
-- 
                   _ _     _ _     _ _
  -Spence         [O.O]   )x.x(   )O.O(
                    O       O      -*-
Newsgroups: rec.puzzles
From: wang@math.psu.edu (Feng Wang)
Subject: Re: blue eyes, brown eyes revisited.
Organization: Department of Mathematics, The Pennsylvania State University
Date: Fri, 16 Oct 1992 20:48:37 GMT

In article <10694@baird.cs.strath.ac.uk> imcc@cs.strath.ac.uk (Iain McCord) writes:
>
> The logical respoe depends on how many blue-eyed islanders there are.
>If there is only one, and he is at the boat, then he knows that he has
>blue eyes and must die.  If there are more than one, then each already 
>knows that there is someone on the island who has blue eyes.  In that
>situation the visitor's statement will have no effect.
>
>-- 
>
>		~~~~~/\~~~~~
>Iain McCord	~~~~/()\~~~~	Fri Oct 16 19:07:39 WET DST 1992
>		~~~~~~~~~~~~


Again?  Should we start another round of reasoning, debating and lecturing?

:-) :-)



I want to add a point to the `revisit' problem.  If the foreigner REvisit
the island after 300 days, all blue-eyes will have been dead and he will
see only brown eyes.  After knowing that it was his word that caused this
tragedy, he may regret and commit suicide too.

If he returns within 300 days, nobody has died yet, is there any way
that he could make it up by saying something and save 300 lives (or
at least part of them)?  I can't think of one solution.  Is there
any solution at all?
From: dwr2560@zeus.tamu.edu (RING, DAVID WAYNE)
Newsgroups: rec.puzzles
Subject: Re: TRAPPED BUBBLE (answer)
Date: 17 Oct 92 00:22:00 GMT
Article-I.D.: zeus.16OCT199219222794
Organization: Texas A&M University, Academic Computing Services
News-Software: VAX/VMS VNEWS 1.41

dsbb@ns1.cc.lehigh.edu (D. SPENCER BEECHER) writes:
>>In a weightless environment a jar of water with an air bubble inside
>>is allowed to come to relative equilibrium (Standard Pressure and
>>Temperature, accelerations = 0, eddies negligible).  What is the
>>appearance and position of the bubble?

The bubble is gravitationally repulsed by the center of mass of the water+jar.
So it will find a corner.

Dave Ring
dwr2560@zeus.tamu.edu
From: chris@questrel.com (Chris Cole)
Newsgroups: rec.puzzles
Subject: Re: Word ending in 5 Consonants (SPOILER)
Date: 9 Oct 92 17:40:35 GMT
Organization: Questrel, Inc.

In article <1992Oct9.013419.17725@nas.nasa.gov> asimov@wk223.nas.nasa.gov (Daniel A. Asimov) writes:
>I admit that I hadn't realized that "lengths" and "twelfths"
>could solve my amended question (nor that "strengths" could
>solve the original one). 
>
>HOWEVER, if you'll still bear with me, no one has suggested the
>word I had in mind, so let me try to narrow it down even more:
>---------------------------------------------------------------
>
>Can you think of a (not too uncommon) seven-letter word, 
>Scrabble-eligible, with the consonant-vowel pattern CVCCCCC
>OTHER THAN the word "lengths" ?
>
>No fair using a computer search of a word-list!!!!
>
>--Daz
> 

I want to apologize to Dan for my erroneous earlier posting saying that
his question was on the rec.puzzles FAQL.  It was not, and neither is this
one.  As penance, I will try to answer his new question.

The only words that I can think of that satisfy his criteria are:
(SPOILER ALERT)

All words occur in Webster's Third New International Dictionary,
Merriam-Webster, Springfield, MA, 1961.

borscht
borshch
borshts
bortsch
dirndls
mightst
samskrt
warmths

If you want six consecutive consonants on the end, but still only
one vowel and one preceding consonant, you have:

borschts
samskrts
From: dougf@neptune.informix.com (Doug Fielder)
Newsgroups: rec.puzzles
Subject: Re: VCR Plus Codes
Date: 12 Oct 92 21:43:43 GMT
Organization: Informix Software, Inc.

In article <1992Oct12.154619.17062@draco.macsch.com> m_reymond@macsch.com writes:
>
>I just got a VCR Plus device (@Fry's in LA for $28.88) and think it's the greatest thing since sliced bread.  No, I am not VCR illiterate. It's just that I have an old VCR which does not have on-screen programming. 
>
>Has anyone out there figgered out how the VCR Plus codes are derived?  
>My inquiry is purely academic. I don't intend to invent my own device.
>I've tried to determine if there is a consistent pattern, but have found none.
>I suspect there is some sort of encryption. I have also noticed that prime time 
>shows on channels 2-13 have codes with the fewest digits.
>
>
>If this has already been answerd in a FAQ, let me know.
>If this is the wrong group for this I apologize and point me in the right direction.


I've been interested in one of these things for a while, but here's my
question:
I don't know about other cities, but in Kansas City, there are about 5
different cable operators in the metropolitan area, and none of the channels
match up.  i.e.  KCTV (CBS) is channel 5.  On one cable service it's channel
3, on another it's channel 7, etc.  Well, TV guide only has one publication
for the whole KC area, so how will the code for a show on channel 5 know
that you are in a region where that is actually cable channel 7?  
I've kind of shied (sp?) away from them because I got the impression they
only worked in a non-cable environment.  

Any answers???

Thanks,
Doug Fielder
Informix Software, Inc.
Lenexa, KS
dougf@infmx.informix.com
From: chris@questrel.com (Chris Cole)
Newsgroups: rec.puzzles
Subject: Re: What's the answer to this ough problem?
Date: 11 Oct 92 08:18:30 GMT
Organization: Questrel, Inc.

In article <baljeual.718587223@uther> baljeual@uther.calvin.edu (Alan Baljeu) writes:
>ough
>
>A long time ago in a spelling book, I learned that there are 4 different
>ways to pronounce the above 4 letter sequence, depending on the word that 
>contains it.  However, that is wrong.  What's the real answer anyone?
>
Well, I think there is no real answer, since reasonable people may disagree
on the pronunciation and viability of words.  For example, below is a list
of twenty-eight possible pronunciations of "ough."

   <sw>     BOROUGH, THOROUGH
   <sw>f    TOUGH
   <sw>k    TURLOUGH (dialectical, obsolete)
   <sw><k_> BROUGH (dialectical)
   <sw>p    HICCOUGH
   <sw>w    BOROUGH, THOROUGH
   <a">     NOUGHT
   <au>     BOUGH
   <a">f    COUGH
   <a">ft   TROUGH (dialectical)
   <a">k    LOUGH (dialectical)
   <a"><k_> DOUGHT, LOUGH (dialectical)
   <a">th   TROUGH (dialectical)
   <o_>     THOUGH
   <o_>g    SKEOUGH (dialectical, obsolete)
   <o_>k    WOUGH (dialectical, obsolete)
   <o_><k_> BOUGHT, HOUGH (dialectical)
   <o.>     OUGHT
   <o.>f    COUGH
   <o.>ft   TROUGH (dialectical)
   <o.>th   TROUGH (dialectical)
   <u">     THROUGH
   <u">f    SOUGH (dialectical, obsolete)
   <u">g    SLOUGHI
   <u">k    OUGH (obsolete)
   <u"><k_> OUGH
   <u.>f    SOUGH (dialectical, obsolete)
   <u.><k_> OUGH

****
Pronunciation Key:
<sw>  the, humdrum
<a">  bother, cot
<a.>  father
<au>  now, loud
<o_>  bone, snow
<o.>  saw, all
<u">  rule, fool
<u.>  pull, wood
<k_>  German ch in ich-laut

Unless noted otherwise, all words occur in Webster's Third New International
Dictionary, Merriam-Webster, Springfield, MA, 1961.
From: radcliff@csd4.csd.uwm.edu (David G Radcliffe)
Newsgroups: rec.puzzles
Subject: Re: Dividing the plane
Date: 15 Oct 1992 03:41:33 GMT
Organization: UW-Milwaukee Math Department
NNTP-Posting-Host: 129.89.7.4

ssd@eos.ncsu.edu (Srikant Sridevan) writes:
: 
:      I don't think this problem (part 2) has a solution. Would love to
: hear from anyone who has one.
: 
: 					Regards,
: 						Srikant
: 						ssd@apollo.psrc.ncsu.edu

Unbelievably, it does.  It is Corollary 5.3 of a paper
by David S. Carter and Andrew Vogt, "Collinearity-preserving
functions between Desarguesian planes," which appears in
the Memoirs of the AMS #235 (1980).  The proof is rather
difficult.  I was hoping that a simple proof could be found,
but I suspect this is not the case.

--
David Radcliffe                                
radcliff@csd4.csd.uwm.edu            
Newsgroups: rec.puzzles,sci.math
From: fmrco!msommer@uunet.uu.net (Mark Sommer)
Subject: math puzzle
Organization: Fidelity Management & Research Co.
Distribution: usa
Date: Wed, 14 Oct 1992 21:14:43 GMT

I'm trying to set up a linear programming problem, with linear
constraints. I've run into a problem others might find
interesting/challenging. 

Consider a linear function on n variables, x1, x2,..., xn:

  c1 x1 + c2 x2 + ... + cn xn

where -1.0 <= xi <= 1.0 and each ci is a real constant. 

Can you set up 1 or more constraints of the form: 

  min_i <= c1_i x1 + c2_i x2 + ... cn_i xn <= max_i

where min_i and max_i are also real constants, such that a solution
can be found (i.e., there exists values for each xi satisfying the
constraints) iff  

  SUM(max(0,xi)) = 1  ?

That is, can you find constraints (constants, noting ci_j can be
different from ci_k, and maxima/minima) ensuring the positive xi's in
the solution sum to 1? 

My apologies if the problem isn't clear.

mark sommer
--
Mark Sommer
Fidelity Management and Research
From: dodson@convex.COM (Dave Dodson)
Newsgroups: rec.puzzles
Subject: Re: Chess problem (answer)
Date: 8 Oct 92 14:56:55 GMT
Reply-To: dodson@convex.COM (Dave Dodson)
Organization: Engineering, CONVEX Computer Corp., Richardson, Tx., USA
Originator: dodson@bach.convex.com
X-Disclaimer: This message was written by a user at CONVEX Computer
              Corp. The opinions expressed are those of the user and
              not necessarily those of CONVEX.

In article <1992Oct7.153531.25752@hsr.no> onar@hsr.no (Onar Aam) writes:
>
>As many discovered, 5 is the smallest number of queens which will force
>checkmate regardless of the kings position.

Oh?  No one has posted an arrangement of 5 queens in which all of them are
be protected.  With the patterns posted, after the queens are placed, it is
possible to place the king so it will be able to capture one of the queens.
Thus the king will not be in checkmate.

----------------------------------------------------------------------

Dave Dodson		                             dodson@convex.COM
Convex Computer Corporation      Richardson, Texas      (214) 497-4234
From: bc@apple.com (bill coderre)
Newsgroups: rec.puzzles
Subject: Hint wanted: Rubik's Tangle
Date: 8 Oct 92 20:34:41 GMT
Organization: Apple Computer Inc, Cupertino, CA


I just got this at a yard sale, and am looking for a clue.

Email or post, either way fine.

thank you
bc
Newsgroups: rec.games.chess
From: "S. Guimont" <HS99@music.mus.polymtl.ca>
Subject: RE: K+Q vs. K+R ending (was: Re: resigning wusses)
Organization: Ecole Polytechnique de Montreal
Date: Thu, 15 Oct 1992 11:09:01 GMT

In article <1992Oct14.184005.24618@pony.Ingres.COM> jrb@Ingres.COM (John Black) writes:
>
>Does anyone have a good reference for KQ vs. KR endings?  The best I've found
>is Keres' "Practical Chess Endings," but I'd prefer a more comprehensive
>treatment.
>
   You can try the "Comprehensive Chess Endings", volume 3 of
Yuri Averbakh in Pergamon press.

   "Comprehensive Chess Endings" having 5 volumes. I give here
the subject of each volumes :

vol 1 : Bishop Endings, Knight Endings
vol 2 : Bishop against Knight Endings, Rook against Minor Piece Endings
vol 3 : Queen and Pawn Endings, Queen against Rook Endings,
        Queen against Minor Piece Endings
vol 4 : Pawn Endings
vol 5 : Rook Endings

  Good eating !

Regards, Dr.S

S. Guimont
RDI - Research and Development Informatik
From: fry@zariski.harvard.edu (David Fry)
Newsgroups: rec.games.chess
Subject: F-S II game 16 moves 1-12
Date: 7 Oct 92 17:57:53 GMT
Article-I.D.: husc3.1992Oct7.135757.16144
Distribution: world
Organization: Harvard Math Department


It's a Benoni!

As of 15:41 GMT
   Spassky Fischer
   (White) (Black)
   1. d4 Nf6
   2. c4 c5
   3. d5 d6
   4. Nc3 g6
   5. e4 Bg7
   6. Bg5 h6
   7. Bh4 g5
   8. Bg3 Qa5
   9. Bd3 Nxe4
   10. Bxe4 Bxc3+
   11. bxc3 Qxc3+
   12. Kf1 f5
Newsgroups: rec.games.chess
From: hyatt@cis.uab.edu (Robert Hyatt)
Subject: Re: human vs computer
Organization: University of Alabama at Birmingham
Date: Mon, 12 Oct 1992 22:26:46 GMT

In article <31271@sophia.inria.fr> gerbaudo@jorasses.inria.fr (Pascal Gerbaudo) writes:
>A GMI, I don't remember who exactly, say in the 70's I think
>that for beating a world champion the computer must
>calculate a depht of 7 moves, 14 half-moves.
>
>(if someone has the complete reference, please send me)
>
>So, if your computer compute over 14 half moves at the speed
>of 40 moves by 2 hours, you play vs a WORLD CHESS CHAMPION.

I think that this came from DeGroot, "thought and choice in chess" and the
idea was that a GM looks about 7plies deep *average* for the entire game.
However, he occasionally looks *much* deeper.  Since current programs
like Cray Blitz average 9-10 and D-T II will go one to two plies deeper
in it's first version, we all outsearch the GM *on average*.  However,
when he chooses to go 40 plies deep in a position where things are
forced, we are hard-pressed to keep up.  Lots of algorithms have
helped, but computers are still quite a ways away.  Even when a computer
beats the world champion, humans will still find occasional deep lines
and win games.  Of course, the computer will often find a "not so deep line"
and win more than it loses....  :^)  In short, it's not only how deep you
search, but *when* you search deeply...  and that is a much harder problem.


-- 
!Robert Hyatt                    Computer and Information Sciences   !
!hyatt@cis.uab.edu               University of Alabama at Birmingham !
Newsgroups: rec.games.chess
From: atten@phil.ruu.nl (Mark van Atten)
Subject: Re: Fischer in the News? Where?
Organization: Department of Philosophy, University of Utrecht, The Netherlands
Date: Tue, 13 Oct 1992 10:53:34 GMT

Dutch television covered the first few games in the News , but then they
dropped the item. Perhaps they'll return to it when Fischer has won the match.
Newspaper coverage continues, though some papers do a far better job than
others.

Mark.
Newsgroups: rec.games.chess