# Propositiones ad Acuendos Juvenes/Problems/6 - De Duobis Negotiatoribus C Solidos Communis Habentibus/Historical Note

## Historical Note on Propositiones ad Acuendos Juvenes by Alcuin of York: Problem $6$: De Duobis Negotiatoribus
It hinges on the fact that a common mean is erroneously being calculated of $2$ for a monetary unit plus $3$ for a monetary unit equals $5$ for $2$ monetary units.
However, Maurice Kraitchik claims in his Mathematical Recreations that it appears in Mahaviracharya's Ganita Sara Samgraha, which dates from c. $850$. However, this has not been corroborated.