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Tiled Floor

Age 11 to 14
ShortChallenge Level Yellow starYellow star
Secondary curriculum
  • Problem
  • Solutions

In Andrea's house, all floors are square, and covered with square tiles.

Tiles along the diagonal are purple, and the other tiles are white, as shown in the diagram.

There are 109 purple tiles on the bathroom floor.

How many tiles are there altogether on the bathroom floor?



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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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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