Ratio and proportion

Andy wants to cycle from Land's End to John o'Groats. Will he be able to eat enough to keep him going?

The triathlon is a physically gruelling challenge. Can you work out which athlete burnt the most calories?

Have you ever wondered what it would be like to race against Usain Bolt?

Is there a temperature at which Celsius and Fahrenheit readings are the same?

Can you find an efficent way to mix paints in any ratio?

Two boats travel up and down a lake. Can you picture where they will cross if you know how fast each boat is travelling?

A garrison of 600 men has just enough bread ... but, with the news that the enemy was planning an attack... How many ounces of bread a day must each man in the garrison be allowed, to hold out 45 days against the siege of the enemy?

Imagine you were given the chance to win some money... and imagine you had nothing to lose...

A Sudoku with clues as ratios.