(12) The fox goes through a customs-post
A fox, a wild-cat and a dog go through a customs-post; they are taxed 111
cash. The dog says to the wild-cat, and the wild-cat says to the fox ‘Your skin
is worth twice mine; you should pay twice as much tax!’ Question : how much
is paid out in each case? Result: the dog pays out 15 cash and 6/7 cash; the
wild-cat pays out 31 cash and 5 parts; the fox pays out 63 cash and 3 parts.
Method: let them be double one another, and combine them [into] 7 to make
the divisor; multiply each by the tax to make the dividends; obtain one for
[each time] the dividend accommodates the divisor.