During the training day Ellie Smith was working with a team on the conundrum Sphinx. The team solved some of their challenges, but didn't have enough time to solve the Size 3 Sphinx.

At the end of the day Ellie asked me how the shape was made. I explained it was constructed from six equilateral triangles ... and left.

Six days later Ellie sent me a photo of the Size 3 solution. Don't look unless you have struggled with this conundrum yourself. She tells me she had a little help from her pal Andy.

A mathematician always asks: How many solutions are there? In this case there are more ways to solve Size 3. Three more ways as far as we know. Can you find them?

Corporate Training is a division of Black Douglas ...