Horses

The Englishman and The Scotsman each had a horse but they couldn't tell them apart. So The Englishman cut The tail off his horse and all went well for a while, but then The Scotsman's horse lost his tail in an accident so they were back where they started. Finally, they consulted The Irishman and he said 'You two are a right pair of fools. Anyone can see that The black horse is three inches taller than The white horse.'