Survo puzzles: www.survo.fi/puzzles --------------------------------------- Copyright (c) Survo Systems 2006-2015 The easiest way to solve these three problems may be using a Javascript application http://www.survo.fi/javascript/SurvoPuzzle.html based on the swapping method. Survo puzzle 372/2015 (80) #343-75502 A B C D 1 3 * * * 17 2 * * * * 24 3 * * * * 37 15 25 29 9 Survo puzzle 373/2015 (270) #353-75508 A B C D E 1 * * * * * 23 2 * * * 12 * 38 3 * * * * * 59 18 11 25 38 28 Survo puzzle 374/2015 (1550) #363-25382 A B C D E F 1 * * * * * * 32 2 * * * * * * 50 3 * * * * * * 89 22 13 43 30 37 26