What? Guess my education has not been as well-rounded as I thought, for I had no idea hat Charlemagne's Puzzle was until I read this article!
Article from
The New York Times:
The Tierney Lab
"Putting Ideas in Science to the Test"
March 3, 2009, 2:12 pm — Updated: 4:25 pm -->
A Prize for Solving Charlemagne’s Puzzle
By John Tierney
You might think that founding the Holy Roman Empire would be enough of a challenge for one man, but Charlemagne wanted more: to conquer mathematical puzzles! If you have the same ambition, you could win a prize here at the Lab.
The emperor hired Alcuin, a renowned English scholar of the eighth century, to compile a collection of puzzles. Titled “Problems to Sharpen the Young,” the book was intended to get the youth of the day more interested in mathematics (a perennial challenge, obviously). Two of Alcuin’s puzzles are included in a new collection,
“The Total Brain Workout,” compiled by Marcel Danesi, a professor of anthropology at the University of Toronto and an expert on puzzles. One of them is a river-crossing brainteaser that’s been found in other collections and cultures, but Dr. Danesi says that Alcuin’s may be the oldest known version:
A traveler comes to a riverbank with a wolf, a goat and a head of cabbage. To his chagrin, he notes that there is only one boat for crossing over, which can carry no more than two passengers — the traveler and either one of the two animals or the cabbage. As the traveler knows, if left alone together, the goat will eat the cabbage and the wolf will eat the goat. The wolf does not eat cabbage. How does the traveler transport his animals and his cabbage to the other side intact in a minimum number of back-and-forth trips?
Once you’ve solved that one, Dr. Danesi offers what he calls a modern classic devised by Boris Kordemsky:
A detachment of soldiers must cross a river. The bridge is broken, and the river is deep. The officer in charge spots two boys playing in a rowboat by the shore. The boat is so tiny, however, that it can only hold two boys or one soldier. All the soldiers succeed in crossing the river in the boat. How?
You submit answers to both puzzles as comments to this post, and you’re welcome to suggest another puzzle for Lab readers. If you get both correct and come up with most intriguing new challenge, you’ll win a prize of Dr. Danesi’s book, “The Total Brain Workout,” which has 450 puzzles designed to stimulate different parts of the brain.
[UPDATE: If you're submitting a new puzzle, don't include the answer in the comment -- you can email it to me separately (tierneylab@nytimes.com). We've already gotten some intriguing new puzzles among the comments. You're welcome to try them and post answers, and to vote for any favorite. And, spoiler alert: In the comments you'll find lots of correct answers to Dr. Danesi's two puzzles.]
