One face of a regular tetrahedron is painted blue and each of the remaining faces are painted using one of the colours red, green or yellow.
How many different possibilities are there? How many different possibilities would there be if the tetrahedron was irregular?
There are many puzzles on the NRICH website, www.nrich.maths.org The NRICH Maths Project provides a free monthly only magazine containing articles, problems, puzzles, games and challenges suitable for all ages. It provides resources for maths clubs, home users and teachers.