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'A Chance to Win?' printed from http://nrich.maths.org/
Imagine you were given the chance to win some money...
and imagine you had nothing to lose...
Imagine you arrive in a room where you are given £128
and six cards (3 red winners and 3 black losers).
You are asked to choose and lay the cards down, one at a time.
You can decide in which order to lay them down.
At each stage you must bet exactly half the money that you have
If you select and play a black card you lose the money you
If you select and play a red card you receive double the money you
(ie. you get the money you bet back, plus that amount again, so if
you bet £64 and win, your total will increase by
If you end up with more money than you started with you get to keep
What's the best order for laying down
What will your strategy be when you are offered 4 or 5 red winning
Use the interactivity below to test out some possibilities.
Draw some conclusions on what strategy to adopt and try to justify
This text is usually replaced by the Flash movie.
We are indebted to Rob Eastaway for introducing us to this problem.