HDTenEightyP/NetNews huggingface dataset:
From: Dave Dodson <dodson@convex.COM>
Subject: Re: ducks and foxes (SPOILER)
Originator: dodson@bach.convex.com
Date: Thu, 13 Aug 1992 21:44:38 GMT
Reply-To: dodson@convex.COM (Dave Dodson)
Organization: Engineering, CONVEX Computer Corp., Richardson, Tx., USA
Keywords: ducks, foxes
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 <13AUG199204265316@zeus.tamu.edu> dwr2560@zeus.tamu.edu (RING, DAVID WAYNE) writes:
>>     A duck is swimming about in a circular pond.  A ravenous fox (who cannot 
>>swim) is roaming the edges of the pond, waiting for the duck to come close.  
>>The fox can run four times faster than the duck can swim.  In order to escape, 
>>the duck must swim to the edge of the pond before flying away.  Assume that 
>>the duck can't fly until it has reached the edge of the pond.
>>
>>     The question is, can the duck escape?  Why or why not?
>
>Suppose the fox runs at a speed 23mph and the duck swims at 5mph. Can
>the duck escape now?

By using the following strategy, the duck can escape as long as the fox
can run no more than v := 4.6033388487517003525565820291030165130674...
times as fast as the duck can swim:

Assume the pond is of radius 1 and the duck swims at speed 1.  The duck
maneuvers to a point 1/v from the center of the pond and diametrically
opposite to the fox.  Then the duck starts swimming radially outward toward
the shore.  Eventually, the fox must decide which way to run around the pond,
or the duck will surely escape.  When the fox starts to run, the duck makes a
90 degree and swims toward the shore such that the fox will have to run more
than halfway around the pond.  If the fox turns around, the duck will turn
back onto an outward radial path until the fox passes colinearity, and then
will turn 90 degrees the other way, which puts the fox in a worse position
than if he had not turned around, so it is not in the fox's best interest to
turn around.

In the above case, the fox runs only 4.6 times as fast as the duck can swim,
so the duck escapes.

The number 4.6033388487517003525565820291030165130674... is the reciprocal of
the solution of the transcendental equation sqrt(1-r*r) = r*(pi+arccos(r)),
which can be derived from the fox's best case where he starts running when
the duck is 1/r+epsilon from the center and doesn't turn around.

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

Dave Dodson		                             dodson@convex.COM
Convex Computer Corporation      Richardson, Texas      (214) 497-4234
From: jtchern@ocf.berkeley.edu (Joseph Hernandez)
Newsgroups: rec.puzzles
Subject: Re: WEST
Date: 18 Aug 92 21:18:50 GMT
Organization: Joseph TeleCommunications Enterprises; Berkeley, California, USA
Via: JTC Enterprises Puzzles and Games Department (Trivia Division)

In article <9817@ncrwat.Waterloo.NCR.COM> tjgerman@53iss6.Waterloo.NCR.COM (Trevor German) writes:

>	An aircraft sets off from city A in a straight line due west
>	at a ground speed of 250mph. How long till it reaches city
>	B 2000  miles due west. Both cities are in Canada.


First, if the aircraft in question capable is not capable of flying 250 mph at 
ground speed, then the question is MOOT! :)

If it is possible, then the obvious answer of 8 hours may apply. But that is
too easy and I am probably missing something. So what gives?

Joe
-- 
-------------------------------------------------------------------------------
            Joseph TeleCommunications Enterprises World Headquarters
*****  *****  *****  jtchern@ocf.Berkeley.EDU          jtcent@soda.Berkeley.EDU
    *    *    *      jhernand@nyx.cs.DU.EDU                    josephhz@IDS.NET
    *    *    *      cb085@cleveland.Freenet.EDU      jph@m-net.ann-arbor.MI.US
*****    *    *****  University of California, Berkeley, California, USA  94720
-------------------------------------------------------------------------------
Newsgroups: rec.puzzles
From: karr@cs.cornell.edu (David Karr)
Subject: Re: Virtual reality puzzle
Organization: Cornell Univ. CS Dept, Ithaca NY 14853
Date: Wed, 19 Aug 1992 04:12:32 GMT

In article <9881@uqcspe.cs.uq.oz.au> warwick@cs.uq.oz.au writes:
>Trivial:  Open up the VR machine in your Real/VR homes, and examine EVERY
>  component.  The VR machine cannot possibly store the details of its own
>  construction (where would it store them?).

Nonsense.  The human body stores the details of its own construction,
in fact it has many millions of copies of the plan.  Read Watson and
Crick for more details.

The mechanism for the VR machine is much simpler: inside is a 500
gigabyte disk (i.e. what an ordinary portable PC carries in 2056 :-)
upon which are recorded all the details of the components of the VR
machine, including an Acme 500 gigabyte 3 ms hard disk which stores
needed data including the details of the components of the VR machine
...

Actually, I think this is a fairly straightforward application of the
Recursion Theorem of computability theory, but I've thought about this
hard enough already.

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



Newsgroups: rec.puzzles
From: russotto@eng.umd.edu (Matthew T. Russotto)
Subject: Re: Three questions for a key
Date: Tue, 18 Aug 92 00:26:16 GMT
Organization: College of Engineering, University of Maryland, College Park
Distribution: w
Keywords: questions

In article <1992Aug17.205628.6965@aplcen.apl.jhu.edu> rtl@ddsdx2.jhuapl.edu (Rick Lopez) writes:
>Disclaimer on the quality of these obscure references:
>
>  I can not claim the responsibility for the difficulty of these questions,
>  but the answers will be rewarding and posted at a later date, if not solved.

 Wild guess
>  2) "An egg, a safe, and a mystery case." What does this refer to?
The Soviet Union, referring to Winton Churchill's statement?

>  3) Emily, John, and Fairleigh. What is this trio also known as?
The three musketeers?  Peter Paul and Mary?  
-- 
Matthew T. Russotto	russotto@eng.umd.edu	russotto@wam.umd.edu
Some news readers expect "Disclaimer:" here.
Just say NO to police searches and seizures.  Make them use force.
(not responsible for bodily harm resulting from following above advice)
Newsgroups: rec.puzzles
From: russotto@eng.umd.edu (Matthew T. Russotto)
Subject: Re: Virtual reality puzzle *spoilers?*
Date: Fri, 21 Aug 92 01:00:43 GMT
Organization: College of Engineering, University of Maryland, College Park

In article <mblum.714279418@chaos.cs.brandeis.edu> mblum@chaos.cs.brandeis.edu (Cerebus) writes:
>
>If you assume the simulation can get every little piece of
>information, you have but to wait until you pass out from: 1. lack of
>sleep; 2. lack of drink; 3. lack of food.  Since sleeping, eating, and
>drinking in a simulation would just be simulated, your actual body
>wouldn't get the benefits from those activities, and so, if you were
>living in a simulation, you couldn't stay conscious long if all these
>were fake.  So you just need to do what seems to be eating, sleeping,
>and drinking, and if, after a few days, everything feels fine, you're
>in reality.

The virtual simulator makers were aware of this one, and either
1) Accelerate your time sense so that by the time your real body
passes out, you die of old age in the simulation or
2) Arrange for some event (earthquake, tornado, slippery spot on the
floor) to knock you out.



-- 
Matthew T. Russotto	russotto@eng.umd.edu	russotto@wam.umd.edu
Some news readers expect "Disclaimer:" here.
Just say NO to police searches and seizures.  Make them use force.
(not responsible for bodily harm resulting from following above advice)
Xref: sparky rec.puzzles:5723 rec.org.mensa:6277
From: clong@remus.rutgers.edu (Chris Long)
Newsgroups: rec.puzzles,rec.org.mensa
Subject: Maximum Product (was Re: Another math question ...)
Date: 18 Aug 92 07:55:41 GMT
Followup-To: rec.puzzles
Organization: Rutgers Univ., New Brunswick, N.J.

In article <1992Aug15.132203.49077@news.th-darmstadt.de>, Ulrich Graef writes:

> Problem:
> ========

> Given the set of ten digits from 0 to 9: 0 1 2 3 4 5 6 7 8 9

> i)   Combine the digits to two numbers x and y and use every
>      digit only once.

> iii) Which are x and y with the maximum product.
>      Examples:

More generally, given the set of digits {0,...,n} form two numbers
such that x*y is maximal.  This is an old chestnut with a nice
(non-computer) solution.
-- 
Chris Long, 265 Old York Rd., Bridgewater, NJ  08807-2618

"In a study of schoolboys, an educator discovered a correlation between size
 of feet and quality of handwriting.  The boys with the larger feet were,
 on the average, older."        Wallis & Roberts, _The Nature of Statistics_
From: shari@room.Princeton.EDU (Shari L. Landes)
Newsgroups: rec.puzzles
Subject: Re: Riddles
Date: 19 Aug 92 19:28:46 GMT
Organization: Princeton University
Originator: news@nimaster

In article <61JRPB1w164w@cellar.org> kml@cellar.org (Lazlo Hoover Toth) writes:
>7 C in a R
>88 C in the S
>
>7 colors in a rainbow
>88 constellations in the sky (? not definite on this one).


You got them both.

harlan


-- 
_________________________________________________________________________
          Only the ephemeral is of lasting value--Ionesco
-------------------------------------------------------------------------
From: jkenton@world.std.com (Jeff Kenton)
Newsgroups: rec.puzzles
Subject: Re: Rhymes
Date: 19 Aug 92 13:45:35 GMT
Article-I.D.: world.Bt8Gw0.32s
Organization: Kenton Systems Corporation, Weston MA

In article <Bt8Ay5.HvD@CAM.ORG> emru@CAM.ORG writes:
>>Can anyone out there rhyme month, hungry, angry or orange?
>>
>>Anybody know words similarly difficult to rhyme?
>

	SILVER is another tough one.


-- 
-------------------------------------------------------------------------
=			Jeff Kenton	(617) 894-4508			=
=			    jkenton@world.std.com			=
-------------------------------------------------------------------------
From: tvaughan@buphyk.bu.edu (tvaughan)
Newsgroups: rec.puzzles
Subject: dead baby puzzle
Date: 17 Aug 92 15:24:01 GMT
Organization: Boston University Physics Department

When my son was born, they quickly made his footprint for identification
purposes.  Afterward, the bottoms of his feet were a dark bluish color.
I am not sure if they would do this identification procedure if he were
a stillborn.  If not, this is a solution.

Tim
From: Tony Lezard <tony@mantis.co.uk>
Newsgroups: rec.puzzles
Subject: Re: Rhymes
Date: Mon, 17 Aug 92 16:39:28 BST
Distribution: world
Organization: Mantis Consultants, Cambridge. UK.

dsbb@ns1.cc.lehigh.edu (D. SPENCER BEECHER) writes:

> Can anyone out there rhyme month, hungry, angry or orange?

An answer for "month"

(n+1)th, as in "First, second, third, ... nth, (n+1)th, ..."

--
Tony Lezard IS tony@mantis.co.uk OR tony%mantis.co.uk@uknet.ac.uk
OR EVEN arl10@phx.cam.ac.uk if all else fails. Great! Kept my .sig down to two
lines!

Newsgroups: rec.puzzles
From: skataba@pbhyf.PacBell.COM (Sam Atabaki)
Subject: NUMBER CREATION USING FOUR "2"s
Organization: Pacific * Bell
Date: Fri, 21 Aug 1992 02:18:18 GMT

Creating numbers using four "2"s and any of mathematical
operators and symbols
such as:                                 __
          +, -, *, /, .(dot), ^(power), V   (square root),
                          _
          ! (factorial), .2 (decimal repeatition), ...


      ********************************************************
Unsolved numbers in the 0-99 range as of (8/20/92):

                     37 38 39
   41          45          49
   51    53       56 57 58 59
   61 62 63    65    67 68 69
70 71    73 74    76 77 78 79
      82 83 84 85 86 87    89
   91 92 93 94 95    97    99


Solved numbers 100-1000:

100 102 108 110 111 112 118 120 121 122 130 132 144 150 180 198
200 216 220 224 225 240 242 243 250 256 288
359 360 361
400 444 482 484 486
500 510 512 514 528 550 574 576 578
600 696 698
710 711 714 716 717 718 719 720 721 722 723 724 726 729 730 742 744
968 1000
      ********************************************************


Examples:   
            1= 22/22
           12= 2*(2+2+2) = (22+2)/2 = 22-2/.2
           20= 2/.2 + 2/.2 = (sqrt(22))^2 - 2

See if you can add to this list. If you post to the group,
please send a copy to me as well.
To get solutions to specific numbers send email.
Any new ideas are welcome.

-Sam Atabaki

Xref: sparky rec.puzzles:5740 sci.math:10376
From: geversti@oasys.dt.navy.mil (Gordon Everstine)
Newsgroups: rec.puzzles,sci.math
Subject: Re: More than one 8 x 8 Magick Square?
Date: 18 Aug 92 18:52:43 GMT
Reply-To: geversti@oasys.dt.navy.mil (Gordon Everstine)
Followup-To: rec.puzzles
Organization: David Taylor Model Basin, Bethesda, Md.

Magic square algorithms are described in, for example, "Magic Squares 
and Cubes" by W.S. Andrews (The Open Court Publishing Co., Chicago, 
1908; may also be available from Dover) and "Mathematical Recreations" 
by M. Kraitchik (Dover, 1953).
Newsgroups: rec.puzzles
From: jil@uts.uucp (Jamie Lubin)
Subject: Re: Riddles
Organization: Bellcore, Piscataway, NJ
Date: Fri, 14 Aug 92 17:32:37 GMT

In article <1992Aug14.162002.28421@Princeton.EDU> shari@room.Princeton.EDU (Shari L. Landes) writes:
>
>I couldn't get the others... but try these...
>
>
>57 H V

Heinz Varities

>1001 A N

Arabian Nights

>8 D a W (In the B S)

Days A Week (In The Beatles' Song)

>12 D of C

Disciples Of Christ

>9 P in the S S

Planets In The Solar System
Newsgroups: rec.puzzles
From: huh@wccf.mit.edu (GENE SIMON HUH)
Subject: ducks and foxes
News-Software: VAX/VMS VNEWS 1.41    
Keywords: ducks, foxes
Organization: MIT - Whitaker College
Date: Thu, 13 Aug 1992 03:31:00 GMT

Dear puzzlelovers,

     I don't think that this one is in the FAQ; please don't flame me too much 
if it is.  I heard it a while ago on a bus somewhere.

     A duck is swimming about in a circular pond.  A ravenous fox (who cannot 
swim) is roaming the edges of the pond, waiting for the duck to come close.  
The fox can run four times faster than the duck can swim.  In order to escape, 
the duck must swim to the edge of the pond before flying away.  Assume that 
the duck can't fly until it has reached the edge of the pond.

     The question is, can the duck escape?  Why or why not?

Cheers

Gene Huh
huh@wccf.mit.edu     or    huh@mitwccf
From: bawagan@rwja.umdnj.edu (Hinayana Bawagan)
Newsgroups: rec.puzzles
Subject: Adam and Eve puzzle
Date: 17 Aug 92 03:39:07 GMT
Distribution: rec
Organization: Robert Wood Johnson Medical School, Piscataway NJ

If this is an FAQ, please excuse me.

     A scuba diver surfaced from the water and found himself in front of
a cave.  He saw at its entrance the naked bodies of a man and a woman.  
Immediately he concluded:  They're Adam and Eve.  WHY?
Newsgroups: rec.puzzles
From: skataba@pbhyf.PacBell.COM (Sam Atabaki)
Subject: NUMBER CREATION USING FOUR "2"s
Organization: Pacific * Bell
Date: Sat, 22 Aug 1992 01:09:28 GMT


Creating numbers using four "2"s and any of mathematical
operators and symbols
such as:                                 __
          +, -, *, /, .(dot), ^(power), V   (square root),
                          _
          ! (factorial), .2 (decimal repeatition), ...

      ********************************************************
Unsolved numbers in the 0-99 range as of (8/21/92):

                     37    39
   41                    
   51    53       56 57  
         63    65    67 68 69
70 71    73 74    76 77 78   
      82    84 85 86 87    
   91 92    94             99


Solved numbers from 100 up to 1000:

100 101 102 108 110 111 112 114 115 116 117 118 119 120 121 122 123
    124 125 127 128 129 130 132 135 142 144 145 150 162 180 198
200 216 220 224 225 236 238 240 242 243 244 250 256 288
300 320 324 358 359 360 361 362
400 405 444 480 482 484 486 495
500 504 510 512 514 525 528 529 550 552 574 576 578 590 598
600 602 610 623 625 627 695 696 698
710 711 714 715 716 717 718 719 720 721 722 723 724 725 726 729 730
    742 744 745
840
900 968 999 1000
      ********************************************************

Examples:   
            1= 22/22
           12= 2*(2+2+2) = (22+2)/2 = 22-2/.2
           20= 2/.2 + 2/.2 = (sqrt(22))^2 - 2

See if you can add to this list. If you post to the group,
please send a copy to me as well.
To get solutions to specific numbers send email.
Any new ideas are welcome.

RESPONDENTS
  * Jaroslaw Tomasz: Made one of the most useful contributions by
      coming up with:  .2^-2 = 25. This solved several numbers.
      He also submitted solutions for 79, 83, 38, 45, 49, 58, 62,
      and a few other ones.

  * Alan Wm Paeth: a solution for 19.
   
  * Ewart Shaw: solutions for 27, 38.

  * Tim Chow: solutions for 38, 45, 49, 79, 83. 

CHALLENGE:
I have already solved the following numbers, can you?
(Of course if you solve any of the unsolved ones, so much better!)
504, 552, 238, 480, 95, 116, 119, 128, 142, 145, 320, 695,  715,
745, 840
                                 _
I have solved 99 with 3 2's: 22/.2   Any ideas for 99? By the
           _
way,  22/.22  is not acceptable.

-Sam Atabaki

Newsgroups: rec.puzzles
From: bmb1021@ultb.isc.rit.edu (B.M. Buck )
Subject: FAQ question...
Originator: bmb1021@ultb
Organization: Rochester Institute of Technology
Date: Sun, 16 Aug 1992 01:51:35 GMT

I'm sure this little puzzle is in the FAQ, but for reasons immediately
obvious, I didn't check there...

Puzzle:  Where can one get a copy of the FAQ for rec.puzzles?

I like puzzles, I like rec.puzzles (even if it does seem a bit
redundant (I know the rule for 11, 21, 1211, 111221, ... already),
and I've seen MANY references to puzzles being in the FAQ, I just
haven't seen the FAQ.  WHERE IS IT???

Thank you for your support.
  Buddha Buck (bmb1021@cs.rit.edu)


Newsgroups: rec.puzzles
From: ronnie@cisco.com (Ronnie B. Kon)
Subject: Re: Riddles
X-Disclaimer: The views expressed in this message are those of an
	      individual at SRI International, and do not necessarily
	      reflect those of the company.
Organization: cisco Systems, Incorporated
Date: Tue, 18 Aug 1992 03:54:01 GMT

In article <1992Aug17.172956.23286@Princeton.EDU>, shari@room.Princeton.EDU (Shari L. Landes) writes:
|> In article <1992Aug14.213109.16597@awdprime.austin.ibm.com> lhmaddox@netmail.austin.ibm.com writes:
|> Here's some of by own...
|> 
|> 48     S in the C U S
States in the Continental United States

|> 100    Y in a C
Years in a Century

|> 7      C in a R
|> 29     D in F (in a L Y)
Days in February (in a Leap Year)

|> 2      E in W   [If you get that, you're doubleplusgood]
|> 4      T Z in the U S
Time Zones in the United States

|> 7      R S on the A F
Red Stripes on the American Flag

|> 12     N on an A C
|> 3      C on a T L
|> 7      D in a L T N (A)
|> 8      L on a S
Legs on a Spider

|> 200    S of P in a R
|> 88     K on a P
Keys on a Piano

|> 88     C in the S
|> 9      D in an A Z C (with the S C)
|> 
|> That's all for now.... Some of them are American Specific, so some Brits
|> might have trouble with a couple of them... :-)
|> 
|> Harlan Landes
|> Gates of Dawn BBS
|> +1 609 426 1618
|> -- 
|> _________________________________________________________________________
|>           Only the ephemeral is of lasting value--Ionesco
|> -------------------------------------------------------------------------

-- 
-------------------------------------------------------------------------------
Ronnie B. Kon           | "Boy, they were big on crematoriums, weren't they?"
ronnie@cisco.com        |
(415) 688-4592          |           -- George Bush at Auschwitz, Sept 1989
-------------------------------------------------------------------------------
Newsgroups: rec.puzzles,sci.math
From: awpaeth@watpix.uwaterloo.ca (Alan Wm Paeth)
Subject: Re: Yet another prime puzzle ! (hard one : ))
Keywords: primes
Organization: University of Waterloo
Date: Thu, 13 Aug 1992 02:06:58 GMT

In <chepan.713587562@gsusgi1.gsu.edu> chepan@gsusgi1.gsu.edu (P. Nambi) writes:
>
>	Let N = 3^(3^p) + 2

Why not generalize the Fermat numbers "2^2P - 1" as "3^3P - 2" instead?
This approach also turns up large primes and is more amenable to computer
search as the series is not hypergeometric (I used Maple).

3^3P-2 still includes factors of five (in fact, the first member: 3^3-2 = 5^2
provides its only perfect square). P = 2 and P = 3 provide primes, followed by
a long dry spell. (P=13 turns up a composite factored as five times a prime).
But despite the related (how??) behavour of the Ferman numbers, a spate of
primes appears later on:

  P = 30, N = 8727963568087712425891397479476727340041447 
  P = 34, N = 4638397686588101979328150167890591454318967698007
  P = 35, N = 125236737537878753441860054533045969266612127846241 

   /Alan Paeth

PS - 5^5P-4 turns up a big    ( 81 digit) prime at P = 23.
     7^7P-6 turns up a bigger (113 digit) prime at P = 19.
From: tjgerman@53iss6.Waterloo.NCR.COM (Trevor German)
Newsgroups: rec.puzzles
Subject: WEST
Date: 18 Aug 92 15:02:19 GMT
Organization: Imaging Systems Division, NCR Corp, Waterloo, Ont., CANADA


	An aircraft sets off from city A in a straight line due west
	at a ground speed of 250mph. How long till it reaches city
	B 2000  miles due west. Both cities are in Canada.
--
       >| "Only average people           | Trevor J German BSc    |<
       >|       never make mistakes."    | NCR, Waterloo, Ontario |<
       >|	               	         | Canada.                |<
Newsgroups: rec.puzzles
Subject: Re: FAQL: unexpected : (Australasian)
From: wft@math.canterbury.ac.nz (Bill Taylor)
Date: 13 Aug 92 21:53:26 +1200
Distribution: world
Organization: Department of Mathematics, University of Canterbury

>    "Aust J Phil" was the *Australasian* and 
>not the *Australian* Journal of Philosophy (which doesn't exist, although
>there are many journals of the form "Australian Journal of X."). 

I hope you don't mean to imply that Australasia doesn't exist. We citizens
of Australasia would object strongly !  (Check with our consul in D.C., or
the Ausralasian ambassador to the U.N.

-----------------------------------------
  Bill Taylor   wft@math.canterbury.ac.nz<--- wherever the hell that is ! 
-----------------------------------------

P.S. (and this could be the puzzle to justify this silly post; but I'll just 
      give the solution):-  There WAS once an Australasian Davis cup team ! 

I suspect there *may* once have even been an Australasian olympic team, long ago. 

(But never a rugby team ! 
     Heavens, there wouldn't be any AustrALIANs on it would there?)
Newsgroups: rec.puzzles
From: tycchow@riesz.mit.edu (Timothy Y. Chow)
Subject: Re: Homographs
Organization: None.  This saves me from writing a disclaimer.
Date: Fri, 14 Aug 92 18:08:40 GMT

In article <1992Aug14.160559.24593@cco.caltech.edu> keith@cco.caltech.edu (Keith Allan Schneider) writes:
<hamel@primate.wisc.edu (Ray Hamel) writes:
<>> I friend recently asked me for two homographs (words spelled the same
<>> but pronounced differently) where one was an adjective and the other a
<>> noun.  He swears there's only one.  I don't believe him, but I've yet to
<>> come up with another example.  
<
<How about lead (pb, the element) and lead (as in you lead, and I'll follow)?

Or rather, lead (as in "lead article").
-- 
Tim Chow     tycchow@math.mit.edu
Where a calculator on the ENIAC is equipped with 18,000 vacuum tubes and weighs
30 tons, computers in the future may have only 1,000 vacuum tubes and weigh
only 1 1/2 tons.                               ---Popular Mechanics, March 1949
Newsgroups: rec.puzzles