Four friends must cross a bridge. How can they all cross it in just 17 minutes?
What's the largest volume of box you can make from a square of paper?
If you have only 40 metres of fencing available, what is the maximum area of land you can fence off?
Manufacturers need to minimise the amount of material used to make their product. What is the best cross-section for a gutter?
Andy is desperate to reach John o'Groats first. Can you devise a winning race plan?