NRICH: Black and Gold Storeys

25 of the storeys of a 50 storey building are painted gold, and the rest are painted black…

A building has 50 storeys. 25 of the storeys are painted black and 25 are painted gold.

The sum of the number of gold storeys in the top half and the number of black storeys in the bottom half of the building is 28.

How many gold storeys are there in the top half of the building?

This problem is adapted from the World Mathematics Championships

You can find more short problems, arranged by curriculum topic, in our short problems collection.

Age 11 to 14


Algebra & Pre-Algebra, Linear Equations
Middle School, High School

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