I recently stumbled on this story. It's very old, and it seems to be well known in Math and Engineering circles. I shared it with my team to give them some idea how to work together and be open to unusual and creative ideas.
Long ago, there was a wealthy man who had 3 sons. Among his most prized posessions were 17 camels. The man was renowned as being very shrewd. In his will, he determined that his oldest son should get 1/2 of his estate(whatever he owned at the time of death), while his second born son should inherit 1/3 of his estate. His youngest son, being the yougest should inherit 1/9 of his estate.
After the father died, the three brothers were quite happy to inherit that wealth. They loved and respected their father very much so they were quite eager to satisfy the will of their father exactly. However, they did not like the idea of killing some of the camels in order to honor the last will of their father:
1/2 of 17 camels makes 8 and 1/2 of a camel figured the oldest brother, 1/3 of 17 camels makes 5 and 2/3 of a camel calculated the second brother, 1/9 of 17 camels makes only 1 and 8/9 camels thought the youngest brother.
A dead camel was not worth much, so it made perfect sense that they hesitated to proceed with the execution of the will. How could have our father made such a mistake in his will? He must have been very bad at arithmetic, they thought. They asked their friends for advice, but nobody really knew what to do in this case. Finally, somebody recommended that they sit with a well known old philosopher. He had solved many difficult problems for the populace, and eager to solve their problem, they followed this advice, bringing their camels to see the old man. The philosopher offered them some tea and listened to their story.
"I agree, this is a difficult problem and I do not know what to do. But please come back tomorrow morning, perhaps I will have an idea overnight".
The next morning they came back and found the old man already expecting them. Says he: "This was indeed a very difficult problem, and I had to think all the night long before I saw how to solve it. Before solving your problem, let me make you a gift. I am very much impressed by your eagerness to honor the will of your father, so I will give you in addition to the 17 camels you already own one more camel out of my own possession."
The three brothers were now very excited, they got a free camel, which was more than they expected with this visit.
"OK," said the old man. "Now let's now try to execute the will of your father. You, the oldest son, how much are you supposed to get?"
"One half of 18 camels," says the oldest son. The philosopher handed the reins of 9 camels to the eldest.
"And you, second son, how much are you supposed to get?"
"1/3, which would be 6 camels," the second son replied. The philosopher handed him the reins to 6 camels.
Finally, he turns to the youngest son and asks him: "How many camels do you get?"
"Well sir," answers the third brother, "I am supposed to get 1/9 of 18 camels which makes precisely 2 camels."
The three brothers take their camels away and discover to their surprise that there is one camel left. (9+6+2 = 17 but there were 18 camels).
"This camel", says the old man, "happens to be my own camel and, although I gave it to you as a present, I will now take it back as a fee for the service I performed by solving the problem".
The three brothers were extremely pleased. No camel had to be killed, and yet the will of their father was completely satified. Full of admiration for the wisdom of the old men, they thanked him many times and left back home. Going over the miraculous solution on the way home, they realized their father must have known arithmetic
much better than they thought originally.
