To see the questions, click here. (Edward Welbourne encoded the list of questions as a web form using ECMAScript to check the answers without giving away the answers; to give it a try, click here.)
To see the answers, click here.
To see one route for deriving the answers, click here. (Note: This solution was kindly sent to me by Shoham Ziv, but I haven't taken the time to check the steps myself.)
To see another route (this one sent to me by Chun Yu James Chen), click here.
To see another route (this one sent to me by Brian Doyle), click here.
To see Martin Henz's description of a solution via constraint logic programming, click here.
To see John Vriezen's discovery of a subtle ambiguity in the wording of the problem, click here.
To see Mark VanDine's description of a solution via genetic algorithms, click here. (Scratch that: in early 2005 he updated his write-up, so you're probably better off clicking here.)
Raymond Boute solved the puzzle by first encoding it in FunMath notation; to see what that looks like, click here. Please send comments to raymond dot boute at pandora dot be.
Christian Schulte and Gert Smolka used the puzzle as an example of a problem solvable with the Oz language; to see their approach, click here.
To see a similar puzzle by Don Woods, click here.
To see a similar puzzle by Kitty Grundman (the sadly deceased feline friend of Helen Grundman), click here; to see the answer, click here.