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Re: Re: Combinatorica questions!!!

  • To: mathgroup at smc.vnet.net
  • Subject: [mg20696] Re: [mg20606] Re: [mg20499] Combinatorica questions!!!
  • From: "vmg" <vgerace at localnet.com>
  • Date: Sun, 7 Nov 1999 02:10:23 -0500
  • Organization: bCandid - Powering the world's discussions - http://bCandid.com
  • References: <7vttl0$lk5$3@dragonfly.wolfram.com>
  • Sender: owner-wri-mathgroup at wolfram.com

  Moving the rook from these two positions is (at minimum) accomplished
in only two moves, and a maximum of 14 if the piece traverses the diagonal
route.


Andrzej Kozlowski <andrzej at tuins.ac.jp> wrote in message
news:7vttl0$lk5$3 at dragonfly.wolfram.com...
> It does seem rather trivial when you look at it the right way. It would
have
> been easier to see if the problem referred the the king, not a rook :)
> --
>
>
> > From: Rob Pratt <rpratt at email.unc.edu>
> > Date: Tue, 2 Nov 1999 02:35:36 -0500
> > To: mathgroup at smc.vnet.net
> > Subject: [mg20696] [mg20606] Re: [mg20499] Combinatorica questions!!!
> >
> > An approach to problem 1 that is simpler than those already given is to
> > recognize that each path consists of a sequence of 14 moves, 7 of them
to
> > the RIGHT one space and 7 of them UP one space.  Hence a path is
uniquely
> > determined by specifying which 7 of the 14 moves are RIGHT (the rest are
> > UP).  We are choosing 7 objects from among 14 positions, so the answer
is
> >
> > Binomial[14,7]=3432
> >
> > Rob Pratt
> > Department of Operations Research
> > The University of North Carolina at Chapel Hill
> >
> > rpratt at email.unc.edu
> >
> > http://www.unc.edu/~rpratt/
> >
> > On Wed, 27 Oct 1999, Keren Edwards wrote:
> >
> >> Hi all!!
> >>
> >> 2 different questions:
> >>
> >> 1.    how many ways does a castle have to reach from the bottom left
side
> >> corner
> >> of a chess board to the upper right corner of the board if he can
> >> move right
> >> and up only?
> >>
> >>
> >>
> >> 2.     you have 8 red identical balls, 9 purple identical balls and 7
white
> >> identical ones.
> >> a.  How many ways can you choose 10 balls with no matter to the
> >> order of the balls?
> >> b.  How many ways can you choose 10 balls with no matter to the
> >> order of the balls, if each color must
> >> be chosen once at least?
> >>
> >>
> >>
> >> Many thanx.
> >>
> >>
> >>
> >>
> >
> >
> >
>
>
>
>



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