Riddle: A rich man in Arabia died, leaving a note for his three sons. It reads: "I have 17 camels. The big brother can get a half of all, the middle can get third of all, and the youngest can get a ninth of all." The brothers are left dumbfounded, since 17 cannot be divided by 2, 3 or 9 without anything left. How can the brothers solve the problem?
Answer: 1. Borrow a camel from their neighbour to make 18 camels. 2. The big brother takes a half of it, so he takes 9. 3. The second brother takes a third of it, so he takes 6. 4. The youngest brother takes a ninth of it, so he takes 2. 5. All the camels that the brothers took add up to 17, leaving the camel they borrowed!