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Elephants and Geese

Age 14 to 16
ShortChallenge Level Yellow starYellow starYellow star
Secondary curriculum
  • Problem
  • Solutions

Yesterday, at Ulaanbaatar market, a white elephant cost the same amount as 99 wild geese.
Overnight, the price of a white elephant fell by 10% and the price of a wild goose rose by 10%.
How many wild geese cost the same amount as a white elephant today?


This problem is adapted from the World Mathematics Championships
You can find more short problems, arranged by curriculum topic, in our short problems collection.

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What is the sum of all the digits in all the integers from one to one million?

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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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