I do not know the answer to this puzzle, and I found it in some old files I had
Many years ago, there was a shepherd with 3 children. One day, while talking to the owner of the herd, the shepherd was praising how smart and creative his children were. His boss decided to put that to a test and called the 3 boys to him. His words were the following:
"Here are 90 sheep. You should take them to the market next Saturday. Lewis, the oldest, will take 50 sheep; John will take 30; and Peter will take 10. The price by which Lewis negotiates his sheep should be the same for the rest of you, i.e. if Lewis decides to sell at 100€ per sheep, John and Peter should sell at the same price. You should sell all the sheep and you should earn equal amounts. I don't want any sheep back and I want to earn money from this."
The following Saturday, the brothers went to the market, sold all the sheep (Lewis sold 50, John sold 30 and Peter sold 10), the price was always the same, and each returned with equal sums of money. How?
Clarification: The price of each sheep and the amount earned by each brother should be higher than 0€. Also, selling between brothers is not considered valid.