[gbrainy] Add rationale to handshake puzzle

[Jordi Mas <jmas src gnome org>]

commit 9534a97da36b3309c90a974921d44db169d91907
Author: Jordi Mas <jmas softcatala org>
Date:   Fri Nov 4 18:51:23 2011 +0100

    Add rationale to handshake puzzle

 src/Games/Logic/PuzzleHandshakes.cs |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/src/Games/Logic/PuzzleHandshakes.cs b/src/Games/Logic/PuzzleHandshakes.cs
index b20292a..26e7bec 100644
--- a/src/Games/Logic/PuzzleHandshakes.cs
+++ b/src/Games/Logic/PuzzleHandshakes.cs
@@ -42,6 +42,9 @@ namespace gbrainy.Games.Logic
 			get { return translations.GetString ("Try to imagine a situation in which you are meeting a small number of people.");}
 		}
 
+		public override string Rationale {
+			get { return translations.GetString ("Using n as the total number of people, the first person handshakes n-1 people, the second n-2 people, etc. The result is the sum of the first n-1 consecutive numbers: 1+2+3+...+(n-1).");}
+		}
 		protected override void Initialize ()
 		{
 			handshakes = 0;