Πῶς δεῖ εὑρίσκειν τὸ δακτύλιον: Byzantine game or a problem from Fibonacci's Liber Abaci? Unpublished notes from Codex Atheniensis EBE 2429

The fourteenth-century manuscript codex Atheniensis EBE 2429 (originally from the Prodromos monastery, Serres) was written for its scribe’s personal use. Among the instructional works that this anonymous scribe excerpted, two intriguing notes are included. They give instructions on how one can find who holds a hidden ring among a group of people using mathematical equations. The same game appears as a mathematical problem in the fifteenth-century collection of problems in manuscript Vind. Phil. Gr. 65 and in the thirteenth-century Liber Abaci by Fibonacci. The connection between these texts is discussed. It is suggested that the problem/game was independently transmitted and possibly has an ultimate Arabic source.