Browsing: Mathematics

Look at the Coca-Cola can in the main image.It is not a can, but an optical illusion – a trick of perspective. Can you work out…

Earlier today I posted five optical illusions by Olivier Redon, a French-American inventor. Here they are again – with demonstrations of how he created the effects.Three…

Earlier today I set you this logic puzzle. Here is is again with the solution.(If you found it too simple. Here’s a harder version.)Head sumsAde, Binky,…

Earlier today I set you these three problems about the number 11. Here they are again with solutions.1. Funny formationYou are the coach of a football…

Earlier today, I set you these three geometrical puzzles. Here they are again with solutions.1. Bonnie TilerBelow left is a square grid with three of its…

The Great Math War: How Three Brilliant Minds Fought for the Foundations of Mathematics Jason Socrates Bardi Basic (2025)In the weeks leading up to September 1891,…

Earlier today I set you the following set of numerical challenges to celebrate the arrival of 2026.Auld lang signsHere is an expression equal to 26 that…

There are many contenders for “world’s greatest invention.” The wheel. The printing press. The steam engine.According to a new book, however, that title should go to…

Earlier today I set a puzzle which is extremely hard to answer if you are not a soap bubble.The four townsFour towns are situated at the…

Today’s puzzle is about transport links and soapy water.The four townsFour towns are situated at the corners of a square, as below:What is the road system…