A few weeks ago a farmer died. And the will he left behind... fortunately his three sons had had a good education. His will was as follows:

• The first son would get 1/2 of the cows,
• The second son would get 1/3 of the cows and
• The third son would get 1/9 of the cows.

At first, everything seems fine. But unfortunately, the farmer had 17 cows. And pieces of cows weren't any good to the sons.

But, since the sons had a good education, they came up with a solution. They lent a cow from the neighbour. Why? Then they had 18:

• 18 * 1/2 = 9 for the 1st son,
• 18 * 1/3 = 6 for the second son and
• 18 * 1/9 = 2 for the third son.

'But what about the neighbour,' you may say. Well, since 9 + 6 + 2 is 17, the cow that was left over went back to the neighbour.

What do you think about the sons' education?