Survo puzzles: www.survo.fi/puzzles
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Copyright (c) Survo Systems 2006-2010

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 219/2010 (480) #443-30068

   A  B  C  D
1  *  *  *  * 13
2  *  *  *  * 47
3  7  *  *  * 23
4  *  *  *  * 53
  43 40 30 23

Survo puzzle 220/2010 (250) #443-96210

   A  B  C  D
1  * 15  *  * 58
2  *  *  *  * 42
3  4  *  *  * 12
4  *  *  *  * 24
  40 38 32 26

Survo puzzle 221/2010 (720) #443-38066

   A  B  C  D
1  *  *  *  * 14
2  *  *  *  * 39
3  *  *  *  * 56
4  *  *  *  * 27
  19 39 33 45