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Voting Paradox

Age 14 to 18
Challenge Level Yellow starYellow star
Secondary curriculum
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How many different possible ways can each of the three voters vote?
For a paradox we are looking for situations in which

(A beats B beats C beats A) or (B beats A beats C beats B) etc.

Try counting the number of ways in which such situations are possible. To reduce the number of cases to analyse, you might consider what happens if two voters agree on their first choice.

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A player has probability 0.4 of winning a single game. What is his probability of winning a 'best of 15 games' tournament?

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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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