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Age 7 to 11
Challenge Level Yellow starYellow star
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Anna and Becky were playing a game. They put one purple cube and two yellow cubes into a bag.

First Anna picked a cube out of the bag without looking, then Becky picked one out.
If the two cubes the girls picked out were the same colour, Anna won the game. If they picked out two differently coloured cubes, then Becky was the the winner.

Is this a fair game?
Explain your answer.

Thank you to Doug Williams from the Mathematics Task Centre Project for this problem. If you'd like to take this idea a bit further, look at In a Box.

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Bipin is in a game show and he has picked a red ball out of 10 balls. He wins a large sum of money, but can you use the information to decided what he should do next?

Trick or Treat

Mrs. Smith had emptied packets of chocolate-covered mice, plastic frogs and gummi-worms into a cauldron for treats. What treat is Trixie most likely to pick out?

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The NRICH Project aims to enrich the mathematical experiences of all learners. To support this aim, members of the NRICH team work in a wide range of capacities, including providing professional development for teachers wishing to embed rich mathematical tasks into everyday classroom practice.

NRICH is part of the family of activities in the Millennium Mathematics Project.

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