You may also like

problem icon


Draw a 'doodle' - a closed intersecting curve drawn without taking pencil from paper. What can you prove about the intersections?

problem icon

Russian Cubes

I want some cubes painted with three blue faces and three red faces. How many different cubes can be painted like that?

problem icon

Areas and Ratios

Do you have enough information to work out the area of the shaded quadrilateral?

A Long Time at the Till

Age 14 to 18 Challenge Level:

Here are some hints: Prime factorisation will probably be useful, as will working in pence rather than pounds and pence.
There are lots of different possibilities to consider, so you will need to be clear with your recording system.
To get a feel for the complexity, it is very unlikely that you will be able to solve the first part of the problem in under two hours.
View full solutions