You may also like

Instant Insanity

Given the nets of 4 cubes with the faces coloured in 4 colours, build a tower so that on each vertical wall no colour is repeated, that is all 4 colours appear.

Magic Caterpillars

Label the joints and legs of these graph theory caterpillars so that the vertex sums are all equal.

Plum Tree

Label this plum tree graph to make it totally magic!

The Great Weights Puzzle

Age 14 to 16
Challenge Level


This problem follows on from 9 Weights

You have twelve weights, one of which is heavier or lighter than the rest, but you don't know which one is heavier or lighter, and a balance. Using just 3 weighings on the balance, can you find a way to identify which weight is the odd one out, and whether it is heavier or lighter?