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?
Manufacturers need to minimise the amount of material used to make
their product. What is the best cross-section for a gutter?
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?