HDTenEightyP/NetNews huggingface dataset:
From: kanad@quip.eecs.umich.edu (Kanad Chakraborty)
Subject: A funnily worded puzzle from a friend.
Organization: University of Michigan EECS Dept., Ann Arbor, MI
Date: Sun, 10 Jan 1993 20:01:45 GMT

This puzzle was given to me by my friend L. Chandar of the Physics
Dept in Syracuse University. Enjoy it, folks !

Kanad

-------------------------------------------------------------------
Here is a card trick:
Suppose, I choose, say, the first 7 cards of each kind, shuffle
them and ask you to mentally think of a number between 1 and 7.
Now, I drop the cards one by one face up.  You count (mentally)
up to the number you have thought and at that point make a mental
note of the new card that I have dropped and once again count
up to this number and repeat this procedure until all 28 cards
have been dropped.  The trick is that I will be able to tell the
last card that you made a mental note of.  For eg, if you thought
of 7 and at the seventh card you see 5, then you count from the
next card onwards (namely the 8th card onwards)up to 5 and then
find 6, count from 13th card up to 6, (ie up to 18th card) now find
4, so count up to 22nd from 19th, then find 5, so you count
up to 27th card from 23rd, now you find 3 and so start to count
from 28th card up to 30th, but cards end by 28th card.  So, now
by looking at you hard enough so that I am able to receive your
mental vibrations, I will be able to tell that the last card
that you made a mental note of in this procedure was 3.
This, however being Kaliyuga, you may spoof at me and claim that
this is just because the final answer (namely 3) is independent of 
the number we start with.  But I will, in the name of Ram (of Babri 
Masjid fame), refute you on this point by asking you to check that
when you try the same experiment a second time, you will invariably
end up at a different answer from the first.  Many strong men will
by now quail and bow before the might of Rama, but this being
Kaliyuga, there will still be some incarnations of Satan in other
such 5-lettered names with even the positions of the vowels being
the same as in Satan, and what's more, with even the same vowel
appearing at those places (!), who will try to refute the theory
of mental vibrations in favour of an evil invention called rationalism.
  
So, after all this bull-shitting, the question is: how does the card
trick work?
--
chandar ( "ch" can be treated as one consonant, and following the
devanagri spirit, "n" before "d" is really not a letter, but just
a "halank", which would therefore mean that this is another example
of a 5-lettered name satisfying the other criteria mentioned above,
only this time in a more subtle fashion [so that even Ram won't 
suspect!])
-------------------------------------------------------------------
From: bruno@cerberus.csd.uwm.edu (Bruno Wolff III)
Newsgroups: rec.puzzles
Subject: Re: pick a number
Date: 8 Jan 1993 05:27:48 GMT
Organization: University of Wisconsin - Milwaukee
Reply-To: bruno@cerberus.csd.uwm.edu
NNTP-Posting-Host: 129.89.7.46
Originator: bruno@cerberus.csd.uwm.edu

From article <1993Jan7.092027.18095@greco-prog.fr>, by loeb@greco-prog.fr (Daniel LOEB):
] 
] "Pick a number from 1 to 1,000,000,000. 
] Your number should be as close as possibly to four-fifthes of the
] average of the numbers chosen by all of the participants."
] 
] How would you play this game? (Send me email, I'll post a summary, and
] indicate which of you would have won.)
] 
A two player game is won (or tied) by choosing 1.
For the multiplayer game there is likely going to be a multiway tie at some
low number. You could try entering several times (under different names?)
choosing different small numbers.
If you can build a large coallition, you could have a big affect on the
average, but in this setting it would be hard to believe that a big enough
collalition could form to be successfull.
Newsgroups: rec.puzzles
From: chil@fraser.sfu.ca (Keith Lim)
Subject: Re: Manhole covers - why circular?
Organization: Simon Fraser University, Burnaby, B.C., Canada
Date: Tue, 5 Jan 1993 19:07:29 GMT

robertw@informix.com (Robert Weinberg) writes:

>Manhole covers are manufactured in circular shape, rather than oval or square, 
>to satisfy one paramount condition.

>What is the condition, and why does a circular shape satisfy it?

Cute answer: because the manhole itself is circular, and a circular manhole
cover (that has a diameter just slightly larger than the hole itself) covers
the hole completely with minumum surface area (i.e., uses least material in
its making.) Manhole covers are circular to fit the manhole.


--        | Simon Fraser University | SFU does not admit to having opinions of
Keith Lim | Burnaby, B.C., V5A 1S6  | its own; any found above are mine only.

At the edge of the final frontier it waits...for Babylon 5 to blow it away.
Star Trek: Deep Space Nine. "To boldly stay where everyone has stayed before."
From: landman@hal.COM (Howard Landman)
Newsgroups: rec.puzzles
Subject: Re: new year's problem
Date: 10 Jan 93 06:40:54 GMT
Distribution: rec
Organization: HaL Computer Systems, Inc.
NNTP-Posting-Host: bang.hal.com

In article <1993Jan2.174010.6177@zip.eecs.umich.edu> kanad@quip.eecs.umich.edu (Kanad Chakraborty) writes:
>E. Gelwan is WRONG.  2013 is not a prime number.

I can see I'll have to atone for my bad guess.  So, here's puzzle which would
be fairly trivial to solve by computer, but might provide some amusement if
done manually.  It's a cryptarithm, That is, you must assign unique digits to
each of the letters to make the formula correct.

	HOWARD * A = LANDMAN

Well, *I* found it amusing anyway.  There's only one solution.

	Howard A. Landman
From: tk@dcs.ed.ac.uk (Tommy Kelly)
Newsgroups: rec.puzzles
Subject: Bus Stop Puzzle
Date: 7 Jan 93 10:57:24 GMT
Reply-To: tk@dcs.ed.ac.uk (Tommy Kelly)
Organization: Laboratory for the Foundations of Computer Science, Edinburgh U

Every morning, I take a train to the city, then have to take a bus to
Uni.  There are two bus stops within easy walking distance of the train
station.

Bus stop 1 is 4mins 20 seconds away, and is the earlier on the route (the bus
visits it before bus stop 2).

Bus stop 2 is 3mins 20 seconds away.

The bus takes about 30 seconds to travel from stop 1 to stop 2.

Bus interarrival time is 15 minutes, and can effectively be at any point
in their run when I begin my walk from the train station.

a. On average, which bus stop should I walk to minimize my time in travelling
   to the University?


b. In general, for times :
	Tn - time to walk to stop n
	dn - time for bus to travel from stop n to stop n+1
	l  - bus interarrival time

	which stop should I choose?

tk	
Newsgroups: rec.puzzles,rec.org.mensa
From: hector@sci.ccny.cuny.edu (Hector Garcia)
Subject: Try this for a change!
Organization: City College of New York - Science Computing Facility
Date: Fri, 8 Jan 1993 20:53:28 GMT

OK, so you may have seen this puzzle many times before.
Excuse me if it has been posted previously!
I don't remember exactly where I saw it first but the instructions 
go something like this:

GOAL:  Connect the pairs of boxes with the same label. ie [1] with [1],
       [2] with [2], and [3] with [3]. The connections must be made by 
       drawing a continuous line sourcing from one of the boxes
       and terminating at the other.
       By a continuous line I mean anything you can draw WITHOUT
       lifting your pencil.


RULES: 1)Lines connecting different pairs of boxes should not intersect.

       2)No drawing is allowed outside of the big box.


                                 This is the big box.
	        _______________ /
	       |     | 1 |     |
	       |     |___|     |
	       |      ___      |
	       |     | 2 |     |
	       |     |___|     |
	       |___         ___|
	       | 3 |       | 3 |
	       |___|       |___|
	       |      ___      |
	       |     | 1 |     |
	       |     |___|     |
	       |      ___      |
	       |     | 2 |     |
	       |_____|___|_____|

Enjoy.

PS/ Topologists, and Graph Theoreticians shall prove the impossibility of this!
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Hector C. Garcia			City College of New York
hector@sci.ccny.cuny.edu		Electrical Engineereing Dept.
eehcg@ees1s0.engr.ccny.cuny.edu
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Newsgroups: rec.puzzles
From: deghare@daisy.uwaterloo.ca (Dave Hare)
Subject: Re: Port Holes
Organization: University of Waterloo
Date: Thu, 7 Jan 1993 13:17:16 GMT

In article <13797@grayt> grayt@Software.Mitel.COM (Tom Gray) writes:
>
>Man hole covers are round because man holes are round.
>
>The puzzle is:
>Why are manholes round?
>
>A more serious problem is:
>Why are ship port holes round?

And an even more serious question is: Why are airplane windows (roughly)
round?
Newsgroups: rec.puzzles
From: boek@mullian.ee.mu.OZ.AU (Christopher Boek)
Subject: Re: Manhole covers - why circular?
Organization: Computer Science, University of Melbourne, Australia
Date: Wed, 6 Jan 1993 07:29:38 GMT

an1060@anon.penet.fi writes:

>X-Anon-To: rec.puzzles

>Anything with a CONSTANT HEIGHT will do.  Circles are the most popular 
>examples, also "triangles" with circular edges (the Mazda Rotary engine uses
>such a design).... Can anyone think of other shapes with a constant height??
>(i.e. shapes that when rolled on a surface along their perimeter yield a
>constant height from the surface)...

A triangle doesn't necessarily satisfy the condition. Consider an equilateral
triangle - the distance from the tip to the centre of the base is less than
the length of a side. Therefore it could slip down the hole if the base (i.e.
one of the sides) is perpendicular to the ground and the lid is close to the
edge of the hole.

Chris.

--
|  ||| |||  |  ||| ||| |||  |  ||Christopher Boek - boek@mullian.ee.mu.oz.au
|  ||| |||  |  ||| ||| |||  |  ||  Dept Elec Eng Univ of Melbourne Australia
|   |   |   |   |   |   |   |   | /  "Anybody remotely interesting is mad in
|___|___|___|___|___|___|___|___| \_/\_/\_/\_/\__/(:*-  some way or another"
From: ross@bryson.demon.co.uk (Ross Beresford)
Subject: Re: does anyone actually post puzzles here?
Organization: Bryson Limited, Reading, UK
X-Newsreader: TIN [version 1.1 PL6]
Date: Tue, 12 Jan 93 20:31:15 GMT

Yes, puzzles do appear occasionally ... don't hold back if you've
got any you'd like people to try.

Actually, I think it's time some of the early classics like
Spoiler by Xrn reappeared for the benefit of the newcomers.

-- 
Ross Beresford
Email: ross@bryson.demon.co.uk           Voice: +44 734 344153
Bryson Limited, 10 Wagtail Close, Twyford, Reading, RG10 9ED, UK
Newsgroups: rec.puzzles.crosswords
From: Bobg@cullen.demon.co.uk (Bob Gregory)
Subject: Rot13 Security
Distribution: world
Organization: Cullen Crosswords
Reply-To: bobg@cullen.demon.co.uk
X-Mailer: Simple NEWS 1.90 (ka9q DIS 1.19)
Date: Tue, 12 Jan 1993 23:49:34 +0000

What's "rot13" security ?

Why is it used ?

What does it secure ?

Thanks ....



     Bob Gregory                                                         
                                                                         
     Cullen Crosswords                  Just because you have paranoia   
     19, Cyncoed Place                  doesn't mean that they're not    
     Cardiff CF2 6SG                    coming to get you                
     United Kingdom                                                      

Newsgroups: rec.puzzles.crosswords
From: tovah@panix.com (Tovah Hollander)
Subject: CWC 28 Winners
Summary: winners of CWC 28
Organization: PANIX Public Access Unix, NYC
Date: Tue, 12 Jan 1993 22:15:37 GMT


My apologies for the delay.  First, everyone else in the office was
sick, so things were hectic.  Then, of course, the bug made it to my
desk...

Anyhow...

The winning clue for Word 1 came from Jake Bergmann
(bergmann@billerica.applicon.slb.com):

	Pervert is to rule on will (10)

The winning clue for Word 2 came from Roger Phillips
(roger@quantime.co.uk):

	I happen to be placed well before the end of January! (8)

I chose the second clue as the best over all, and have asked Roger to
moderate CWC 29.

In addition, there was a special bonus section.  All of the following
clues have something which needs to be changed before the clue can be solved
(the same thing in each clue).

Explanation (rot13'ed):
	Rnpu pyhr pbagnvaf n fcbbarevfz (r.t., PNHTUG FJBEQ/FBHTUG PUBEQ
	be UVG N TANG/XAVG N UNG).

(Hmmm... just noticed that GNAT when rot13'ed is itself, reversed.)

Special clues for Word 1
------------------------

	Decision to ransack Ryan's loot (10)

	Remove two rules in Congressional decision (10)

	Lunch motion sure to be agreement (10)

Special clues for Word 2
------------------------

	First appearance on day that cur was married (8)

	January fix ceased backing up of hot water pipe somewhat (8)

Special clue for a different word
---------------------------------

	Dutchman's crew splitting tie (9)

I'll post the complete list of clues, with comments, later today or first
thing tomorrow.  Thanks again for being patient with this patient.

-- 
Tovah Hollander
tovah@panix.com -or- tovah@onion.salad.mssm.edu
From: mara@panix.com (Mara Chibnik)
Newsgroups: rec.puzzles.crosswords
Subject: CWC 28:  results delayed
Date: 11 Jan 93 14:52:09 GMT
Organization: (getting there)


Tovah asked me to apologize for the delay.  She's home ill today
and will announce the results of CWC 28 as soon as she is back 
at work.

I'd love to suggest that there is a secret message embedded in the
above, but if there is I didn't put it there deliberately.





-- 

  Mara Chibnik
  mara@panix.com                Life is too important to be taken seriously.
Newsgroups: rec.puzzles.crosswords
From: schieb@shark.gsfc.nasa.gov (Brian D. Schieber)
Subject: does anyone actually post puzzles here?
Reply-To: schieb@shark.gsfc.nasa.gov (Brian D. Schieber)
Organization: Oceans & Ice Branch, NASA/GSFC/GSC
Distribution: na
Date: Thu, 7 Jan 1993 14:00:59 GMT
From: tomd@bali.amd.com (Tom Deneau)
Newsgroups: rec.puzzles.crosswords
Subject: ACC16 Winner
Date: 11 Jan 93 17:41:09 GMT
Organization: Advanced Micro Devices, Austin TX


Sorry for the delay in getting these results out.
Here is the winning clue for ACC16, a contest
that started back before the holidays.

	Of pre-lay stimulation... (8)

This clue was submitted by Viresh Ratnakar and I
invite Viresh to start ACC17 at his convenience.

I will post the complete list of clues and
comments separately.



-----------------------------------------------------------------
 Tom Deneau                    {uunet, cs.utexas.edu!ames}!amdcad!cayman!tomd
 Advanced Micro Devices, Austin TX     +1 512 462 4952     tom.deneau@AMD.COM
From: hamel@uakari.primate.wisc.edu (Ray Hamel)
Newsgroups: rec.puzzles.crosswords
Subject: Reaching Greg Lawler
Date: 7 Jan 1993 11:28:59 -0600
Organization: UW-Madison Primate Center
NNTP-Posting-Host: uakari.primate.wisc.edu


	I'm having the same trouble reaching Greg Lawler for
PCWC8 as I did the last time he hosted PCWC -- my mail to him
simply bounces back.  
	Greg -- please contact me directly at hamel@primate.wisc.edu.
Thanks.

Ray Hamel
University of Wisconsin
Newsgroups: rec.puzzles.crosswords
From: roger@quantime.co.uk (Roger Phillips)
Newsgroups: rec.puzzles.crosswords
Subject: CWC 29
Date: 12 Jan 93 19:26:02 GMT
Reply-To: roger@quantime.co.uk (Roger Phillips)
Organization: Quantime Ltd, London (software for market research)

Tovah Hollander has asked me to bring you...

         CLUE WRITING COMPETITION NUMBER 29

Welcome to the Clue Writing Competition 29 (devised by Ian Gent).  The
rules, and this article, are much the same as used in earlier rounds.

The dates for CWC 29 are:

    Wed 20 Jan 93 23:59 GMT  Deadline for CWC29 entries.
    Thu 21 Jan 93            I'll post the CWC29 winners.
    Thu 21 Jan 93            I'll post an annotated list of entries.

The rules:

Later on in this posting you'll find two words or phrases.  The first 
is chosen to be fairly easy to write a clue for; the second is intended 
to be more awkward.  

You may submit clues for either or both words.  I will accept only one
clue per person for each word; If you send more than one for a word, I
will accept the first one I receive.  E-mail the clues, along with your
name and e-mail address, clear explanations of how your clues work, and
whether or not you could run the next contest, to me at the following
address:

    roger@quantime.co.uk

After the deadline, I'll pick my favourite clue for each word; thus
there will be two winning clues.  I'll pick my favourite of these two
as the overall winner, inviting its writer to set the next round of
this competition.  I'll post separately a list of all the clues, with
as much commentary as I see fit.

IMPORTANT: Please DO NOT post your own clues, or anything else that
might give away the answer words!  Some readers of this group want to
try solving the winning clues; please don't spoil it for them.

The words for CWC29 follow, "rot13" encoded for extra security,






















URYVPBCGRE

ZNPEBOVBGVP

-- 
Roger Phillips                            roger@quantime.co.uk
"*ghost-word* a word that has originated in the blunder of a
scribe or printer - common in dictionaries"
-- Chambers Twentieth Century Dictionary (1952)
From: kanad@quip.eecs.umich.edu (Kanad Chakraborty)
Subject: An *easy* puzzle.
Organization: University of Michigan EECS Dept., Ann Arbor, MI
Date: Fri, 8 Jan 1993 19:33:14 GMT

Here's a very *easy*, and nice, puzzle.  This puzzle is a close
relative of the one I posted on New Years' eve.  No flames, please,
for posting something so simple. Simple things can be interesting 
sometimes, as some of you would undoubtedly agree.

Suppose you are given 3 colors and asked to assign a color
to each point in a plane such that (a) you *must* use more than one
color for the entire plane; (b) *every* pair of points 1 inch apart
are colored alike.  Can you make such an assignment ? The plane is
a continuum of points, it is not a grid.

Kanad
From: barryg@hplsla.hp.com (Barry Gunn)
Date: Wed, 6 Jan 1993 21:02:37 GMT
Subject: Re: Help Needed for Bob Puzzle
Organization: HP Lake Stevens, WA
Newsgroups: rec.puzzles

>/ hplsla:rec.puzzles / Gordon_Wong@mindlink.bc.ca (Gordon Wong) /  7:42 pm  Dec 30, 1992 /
>Has anyone seen this puzzle before? What's the answer to it?
>
>Bob opens up the newspaper and reads a story about a woman (Bobbi)
>who skiied over a cliff and died while on a vacation with her
>husband (Rob). Bob calls up the police and tells them to arrest
>Rob for murder. Why?
>
>
>----------
Bob sold Rob the plane tickets to the vacation. He bought himself a 
round-trip ticket- but he got his wife a one-way.


     _
    [o] Barry Gunn x2281
    /|\ barryg@lsid.hp.com
Newsgroups: rec.puzzles
From: ping@bnlux1.bnl.gov (Shiping Zhang)
Subject: Re: Bus Stop Puzzle
Organization: Brookhaven National Laboratory, Upton, NY 11973
Date: Thu, 7 Jan 1993 18:42:14 GMT

In article <C0HD3p.1u4@dcs.ed.ac.uk> tk@dcs.ed.ac.uk (Tommy Kelly) writes:
>Every morning, I take a train to the city, then have to take a bus to
>Uni.  There are two bus stops within easy walking distance of the train
>station.
>
>Bus stop 1 is 4mins 20 seconds away, and is the earlier on the route (the bus
>visits it before bus stop 2).
>
>Bus stop 2 is 3mins 20 seconds away.
>
>The bus takes about 30 seconds to travel from stop 1 to stop 2.
>
>Bus interarrival time is 15 minutes, and can effectively be at any point
>in their run when I begin my walk from the train station.
>
>a. On average, which bus stop should I walk to minimize my time in travelling
>   to the University?

  Probably you meant 3'20" for stop 1 and 4'20" for stop 2. But according
  to the above info, always walk to bus stop 2. The worst could happen is
  to get on the same bus you would if walking to bus stop 1. With luck,
  you could catch a bus 15 min earlier.

-ping

Newsgroups: rec.puzzles,sci.math
From: pratt@Sunburn.Stanford.EDU (Vaughan R. Pratt)
Subject: Re: Combinatorical problem
Organization: Computer Science Department,  Stanford University.
Date: Tue, 12 Jan 1993 19:19:09 GMT

In article <greil.726829446@guug.de> greil@guug.de (Anton Greil) writes:
>mnewman@comlab.ox.ac.uk (Matthew Newman) writes:
>
>>Does anyone know the status on the following problem ?
>
>>Let S(n) be the set of all permutations of the integers 1..n
>>Let T(n) be the set of all transpositions (i.e. swapping
>>two numbers).
>
>>For which n can one find a set B(n) such that for all p in S(n)
>>either p is in B(n), or p differs by exactly one transposition
>>from an element of B(n), and such that no two elements from B(n)
>>differ by exactly one transposition ?

All n.  Take B(n) = A(n), the alternating subgroup of S(n) consisting
of all even permutations of S(n).  (The other coset, S(n)-A(n), will do
equally well.)  Every even permutation is in B(n), every odd
permutation is one transposition away from an element of B(n), and any
two elements of B(n) are at least two transpositions apart.

>
>I'd like to append with a more general question:
>
>T(n) forms a generating system for S(n)  (for all n).
>How can the combinatorics of this generating system be characterized?

T(n) constitutes the edges of a regular undirected graph on S(n) (all
vertices have the same degree).  The distance between p and q is n-c
where c is the number of cycles in pq^-1.  (Proof: by induction on
distance.  The identity has n cycles, and every transposition increases
or decreases the number of cycles by 1.)  Hence the diameter is n-1,
with those p,q for which pq^-1 is cyclic being antipodal.

>Especially: does there exist a normal form of each generated element from
>S(n) over the base T(n) ?

The following normal form minimizes number of transpositions.

To form (A1 A2 ... An), for each i from 1 to n-1, transpose i and Ai if
necessary.  E.g. to form (4 2 1 3) start from (1 2 3 4) and proceed thus:

	Transposition	  Result
			(1 2 3 4)
	1 <-> 4 	(4 2 3 1)
	2 <-> 2		unnecessary
	3 <-> 1		(4 2 1 3)

This can be seen to achieve the above distance n-c, and hence is is
minimal.

Another normal form is to implement each cycle starting from the least
element of each cycle.  This is just a permutation of the above normal
form: any two noninterfering transpositions (transposition pairs
involving four locations) commute, in particular transpositions from
distinct cycles.  Hence it is equally efficient.
-- 
Vaughan Pratt			There's safety in large condition numbers.
Xref: sparky rec.puzzles:8325 sci.math:17971
From: mnewman@comlab.ox.ac.uk (Matthew Newman)
Newsgroups: rec.puzzles,sci.math
Subject: Combinatorical problem
Date: 11 Jan 93 17:10:53 GMT
Organization: Oxford University Computing Laboratory, UK
Originator: mnewman@client40.comlab

Does anyone know the status on the following problem ?

Let S(n) be the set of all permutations of the integers 1..n
Let T(n) be the set of all transpositions (i.e. swapping
two numbers).

For which n can one find a set B(n) such that for all p in S(n)
either p is in B(n), or p differs by exactly one transposition
from an element of B(n), and such that no two elements from B(n)
differ by exactly one transposition ?

If such a B(n) exists, then it is of size n!/[1+n(n-1)/2] since
each element from B(n) differs by exactly one transposition from
n(n-1)/2 elements from S(n), thus we can rule out n=3,4,5. It is
trivially possible for n=2, and in 1974 (!) no other affirmative
solution was known.
Newsgroups: rec.puzzles