The following was used as the basis of a TV show to illustrate the difference between the way a human mind approaches such a problem and the brute-force approach of a computer that finds the solution by trying all 40,320 possible arrangements of the digits:

Place the digits 1 through 8 in the eight circles shown in the diagram, but with this restriction:
No two digits next to each other in serial order may go in circles that are connected by a direct line.
(For example, if 2 is placed in the top circle, neither 1 nor 3 may be placed in any of the three circles in the horizontal row beneath it, because each of these circles is connected to the top circle by a direct line.)

There is only one solution , not counting rotations or mirror images.



 

Solution to the Problem:




Correctly solved by:

1. Richard Johnson La Jolla, California
2. Akash Patel Columbus, Georgia
3. Walt Arrison Philadelphia, Pennsylvania
4. Jeffrey Gaither Winchester, Virginia
5. Bill Funk San Antonio, Texas
6. Erik Stenbäcka Tullängen, Sweden
7. John Funk Ventura, California
8. Misty Carlisle Winchester, Virginia
9. Lucy Flournoy Columbus, Georgia
10. Kirstine Wynn St. Olaf College
Northfield, Minnesota
11. Franklin Harcourt Columbus, Georgia
12. James Alarie University of Michigan -- Flint
Flint, Michigan
13. Victor Larsson, Frida Öijerholm Tullängen, Sweden
14. Ali Alatabi and Christoffer Axelsson Tullängen, Örebro, Sweden
15. Dave Smith Toledo, Ohio
16. Scott Valare Toledo, Ohio
17. Ashleigh Rogers Winchester, Virginia
18. Mary Margaret Columbus, Georgia
19. Murray Georgia
20. Mitchell Lane Columbus, Georgia
21. David & Judy Dixon Bennettsville, South Carolina
22. Patrick Mize Columbus, Georgia
23. Nate Wilson Winchester, Virginia
24. Celeste Doerwaldt Winchester, Virginia
25. Brad Stillwagon Winchester, Virginia
26. Laura LaRusso Winchester, Virginia
27. Graham Foster Winchester, Virginia
28. Matt McMurtry Arlington, Virginia
29. Bec11189 ----------
30. Jo Monhollen Winchester, Virginia
31. BreathStealer Columbus, Georgia
32. Joo-Ri Lee Columbus, Georgia