Survo puzzles: www.survo.fi/puzzles --------------------------------------- Copyright (c) Survo Systems 2006-2014 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 354/2015 (1000) #443-57384 A B C D 1 * * * * 40 2 * * * * 30 3 * * * * 18 4 * * * * 48 51 16 45 24 Survo puzzle 355/2015 (540) #443-11338 A B C D 1 * * * 3 33 2 * * * * 31 3 * * * * 53 4 * * * * 19 37 27 54 18 Survo puzzle 356/2015 (400) #443-7430 A B C D 1 * * * * 46 2 * * * * 23 3 * * 11 * 31 4 * * * * 36 13 54 45 24