Newsgroups: rec.puzzles, alt.radio.networks.npr
Followup-To: alt.radio.networks.npr
From: hoey@aic.nrl.navy.mil (Dan Hoey)
Date: 1996/03/21
Subject: NPR Sunday Puzzle for 17 March

The Weekend Edition Sunday puzzle this week was exceptionally good:

:  Start with a grid of 5x5 unit squares, which may be considered to
:  be made up of 60 unit line segments.  What is the smallest number
:  of segments that can be removed so that no square of any size
:  remains?

Since I live in NPR's home town, I can't listen to the puzzle on the
radio, but a friend sent me an e-mail copy.  It's too late to send
your answers to puz...@NPR.org, but you may want to try your hand at
solving the puzzle between now and the answer broadcast on 24 March.

I've found some solutions with proof of minimality (hint: gur nafjre
vf abg svsgrra), after which I wrote a program that generated all the
solutions.  I plan to post that to rec.puzzles next week.

Dan
Hoey@AIC.NRL.Navy.Mil