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From Josh of Alameda School, Ampthill, Beds:

There are 5 presents in the second pile, 2 presents in the first pile, 3 presents in the third pile and 10 in the fourth pile.

I worked it out by saying the second pile equalled x. The first pile would then be x-3, the third pile x-2 and the fourth pile was 2x.

Simplified this gave me 5x-5 = 20. So 5x = 20+5. 5x = 25. And so x, the number of presents in the second pile, is 5.


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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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