The mean of three numbers x, y and z is x.

What is the mean of y and z?

This problem is taken from the UKMT Mathematical Challenges.

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

Simultaneous equations. Mathematical reasoning & proof. Expanding and factorising quadratics. Generalising. Circle properties and circle theorems. Regular polygons and circles. Polynomial functions and their roots. 2D shapes and their properties. Creating and manipulating expressions and formulae. Inequalities.