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Chris and Jo decide to play a game.
They put some red and some blue ribbons in a box.
They each pick a ribbon from the box without looking (and without replacing them).
Jo wins if the two ribbons are the same colour and Chris wins if the two ribbons are a different colour.
How many ribbons of each colour would you need in the box to make it a fair game?
Is there more than one way to make a fair game?
This problem is based on one offered by Doug Williams at the 2003 ATM conference in Bath UK. See also http://www.blackdouglas.com.au/taskcentre