Who gets half a camel? 

Watch the full lecture here: www.gresham.ac...
Many puzzles have a long history, such as water pouring puzzles, where you need to measure (for example) one pint of water equipped only with an eight-pint and a five-pint jug. The mathematics behind the solution has many useful applications.
Meanwhile, paradoxes such as: “some men shave themselves; those that do not shave themselves are shaved by the barber: who shaves the barber?” lead us to deep questions about set theory.
An excerpt taken from a lecture by Professor Sarah Hart called 'Mathematical Puzzles and Paradoxes'