A mathematical conundrum from a thousand years ago
A father dies leaving instructions that his 17 camels are to be split up between his 3 sons as follows -
half the camels are to go to the eldest son
a third of the camels are to go to the middle son
and a ninth of the camels are to go to the youngest son
Failing to think of a way of carrying out their father's wishes, they decided to seek help. So they sent a message across the desert to their uncle, who though poor was considered to be wise.
A month later, up rode their uncle on his grotty old camel. After he'd had a rest and something to eat, they explained their problem to him.
"Tell you what", he said, "I'll lend you my camel, then you'll have 18, and you should be able to divide them up without difficulty."
So the eldest son chose his 9 camels from the flock, the middle son chose his 6 camels, and the youngest son chose his 2 camels. Uncle then got back on his camel (which no-one had chosen because it was old and grotty) and rode back home across the desert (no doubt muttering to himself about the failings of the younger generation).