The following problem is found in the first Norwegian arithmetic, published in 1645 by Tyge Hansøn:
Three hundred oxen large and small,
A cattle owner wanted to buy:
3 for 63 daler he got.
Again, he let them sell,
3 for 63 daler they fetched,
both slim and fat.
787$1\over 2$ daler was his profit.
Tell me, how did that happen?
Whoever wants to calculate that, consider rightly
and argue the issue well.
Then it becomes quite simple.
to calculate for a farmer.
So apparently, the cattle owner bought and sold for the same price, but he still made a profit. There is no solution to this problem in the text. I have a puzzle-like solution, but would like to hear other suggestions before I reveal it.
The original is written in verse, with rhymes. I have translated the text into modern English, but had to sacrifice some of the poetic effects in order to preserve the factual content.
In the coinage system used in Denmark-Norway at the time, one daler could be divided into 96 skillings. The problem is found in a chapter on the rule of three, so a solution should in some way be true to the principle of proportionality. Hence, any suggestion that the herd has increased in size, or similar ideas, would not be satisfactory.
And if anyone has seen a similar problem, I would be very interested in hearing about it.