### All in the Mind

Imagine you are suspending a cube from one vertex and allowing it to hang freely. What shape does the surface of the water make around the cube?

### 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.

### Is There a Theorem?

Draw a square. A second square of the same size slides around the first always maintaining contact and keeping the same orientation. How far does the dot travel?

# Cogs

##### Age 11 to 14Challenge Level

A and B are two interlocking cogwheels having p teeth and q teeth respectively where $$3\leq q\leq p \leq 12$$

One tooth on B is painted red. Find the values of p and q for which this red tooth on B contacts every gap on the cogwheel A as the wheels rotate.