Making a meal of maths

For those of you who have spent the past week counting sheep - or, rather, trying to find the answer to the maths problem posed to school pupils in this year's UK maths challenge - The Diary has the solution.

The question was: "It is claimed that a lion can eat a sheep in four hours, a leopard can eat a sheep in five hours, while a bear takes six hours to eat a sheep. How long would it take all three of them to eat a single sheep?" Think about it in terms of how much each animal can eat per hour, then work out how much all three get through in an hour. The answer, in hours, is 60 over 37 or 1.621 recurring.