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