Survo puzzles: www.survo.fi/puzzles --------------------------------------- Copyright (c) Survo Systems 2006-2012 The easiest way to solve these three problems may be using a Java Applet http://www.survo.fi/swap/puzzles.html based on the swapping method. Survo puzzle 285/2012 (75) #443-27402 A B C D 1 * * 13 * 35 2 * 14 * * 57 3 * * * 2 25 4 4 * * * 19 35 31 50 20 Survo puzzle 286/2012 (60) #443-16172 A B C D 1 * * 7 * 41 2 * 3 * * 11 3 * * * * 57 4 8 * * * 27 42 38 24 32 Survo puzzle 287/2012 (1400) #442-74472 A B C D 1 * * * * 24 2 * * * * 47 3 * * * * 53 4 * * * * 12 31 43 23 39