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Why do this problem?

A simple context lending itself to the use of a tree diagram.

Key Questions

What is unknown?

How can we record the information?

Can we form an equation from the information given?

Possible Support

Try How Many Balls? and Fixing The Odds


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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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