Mr L's Projects

Probability Race

Note: You can play this game on this site or on the Scratch website.

Roll two dice and add the scores together to see which animal advances towards the finish line.

Is the race fair?

Some animals start further back than others. When you played the game, did it seem like those animals moved more than the closer ones? How would you know for sure? One way is to list all the possible rolls we could get. Use the chart below to work out how likely each animal is to move. Hint: each animal will have a ?/36 chance of moving each turn.

Yes, but it is completely fair?

OK... lets run a simulation to find out. If you play a large number of games, maybe 100 or even 1,000, you will start to see a pattern.

Press the 'w' key in-game to do this. To warp really fast, activate turbo mode (hold control and click the green flag). Press 't' to see the current win tally, and press 'f' to see a frequency chart of the wins so far (exit turbo mode first for best results). When warping, press 'c' to cancel.

chart