Proposition: 7.33: Least Ratio of Numbers
(Proposition 33 from Book 7 of Euclid's “Elements”)
To find the least of those (numbers) having the same ratio as any given multitude of numbers.
 Let $A$, $B$, and $C$ be any given multitude of numbers.
 So it is required to find the least of those (numbers) having the same ratio as $A$, $B$, and $C$.
Modern Formulation
To find the reduced ratios of $\frac AB$ and $\frac BC,$ i.e. such that $A,$ $B$ and $C$ are mutually coprime.
Table of Contents
Proofs: 1
Mentioned in:
Proofs: 1 2 3 4 5 6
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References
Adapted from (subject to copyright, with kind permission)
 Fitzpatrick, Richard: Euclid's "Elements of Geometry"
Adapted from CC BYSA 3.0 Sources:
 Prime.mover and others: "Pr∞fWiki", https://proofwiki.org/wiki/Main_Page, 2016