Survo puzzles: www.survo.fi/puzzles --------------------------------------- Copyright (c) Survo Systems 2006-2013 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 312/2013 (15) #343-32074 A B C D 1 * * 9 * 39 2 * 10 * * 23 3 5 * * * 16 23 29 15 11 Survo puzzle 313/2013 (60) #343-55258 A B C D 1 * * * * 16 2 * * * 3 25 3 * * * * 37 29 18 23 8 Survo puzzle 314/2013 (140) #343-59860 A B C D 1 * * * * 26 2 * * * * 38 3 * * * * 14 18 23 28 9