No Magic In A Knight's Tour

morgothan writes "As reported in an article on Math World the solution, or rather lack of solution has been found to the over one hundred fifty year old math problem of how many numbers of magic tours a knight can make on a standard 8x8 chessboard. It turn out that there exist one hundred forty distinct semimagic tours, but no magic tour. The solution came after 61.40 CPU-days, corresponding to 138.25 days of computation at 1 GHz, the project was completed on August 5, 2003 in which every possible enumeration was tried out. The author of the software that finally solved the problem has also put up a webpage in which he further explains the problem and his method of solving it." Thanks to Mig for pointing out a great background page on Chessbase.com.

Comments

Another interesting math problem

[Anonymous Coward]

I've been doing a bit of thinking about the Monty Hall Problem, where assuming the following occurs:

• You are on a famous game show and being presented with three doors, behind one of which there is a fantastic prize, and the other two lesser prizes or sand or something.
• You choose one of the doors.
• The host opens one of the remaining doors to demonstrate that it does not contain the fantastic prize, and offers you the opportunity to switch your choice.

Do you? Mathematically speaking, I've always been told that you should, because your first choice was a 1 in 3 shot but after the door has been opened you are being given a 1 in 2 opportunity.

However, I just wrote a quick demonstration program, and found out that this isn't the case, and as you've probably expected it really is 1 in 3 no matter which way you go. You win this one, high school math teacher.