Propositiones ad Acuendos Juvenes/Problems/9 - De Sago/Historical Note

Historical Note on by : Problem $9$: De Sago
According to the translator, the explanation for the answer given in the original manuscript was "not enlightening".

It is supposed that a scribe may have skipped a line when transcribing it.

The text as given by makes little sense:
 * The eightieth part of $400$ is $5$ and the hundredth part of $400$ is $4$.
 * Both eighty $5$s and one hundred $4$s give the same result, $400$.
 * There are that many cloaks.