Greek Anthology Book XIV: Metrodorus: 146

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Arithmetical Epigram of Metrodorus

$A$. Give me two minas and I become twice as much as you.
$B$. And if I got the same from you I am four times as much as you.


Solution

Let $a$ minas be the quantity of $A$.

Let $b$ minas be the quantity of $B$.


We have:

\(\text {(1)}: \quad\) \(\ds a + 2\) \(=\) \(\ds 2 \paren {b - 2}\)
\(\ds a + 2\) \(=\) \(\ds 2 b - 4\)
\(\ds a\) \(=\) \(\ds 2 b - 6\)
\(\text {(2)}: \quad\) \(\ds b + 2\) \(=\) \(\ds 4 \paren {a - 2}\)
\(\ds \leadsto \ \ \) \(\ds b + 2\) \(=\) \(\ds 4 a - 8\)
\(\ds \leadsto \ \ \) \(\ds b\) \(=\) \(\ds 4 a - 10\)
\(\ds \leadsto \ \ \) \(\ds a\) \(=\) \(\ds 2 \paren {4 a - 10} - 6\)
\(\ds \) \(=\) \(\ds 8 a - 20 - 6\)
\(\ds \leadsto \ \ \) \(\ds 7 a\) \(=\) \(\ds 26\)
\(\ds \leadsto \ \ \) \(\ds a\) \(=\) \(\ds \frac {26} 7\)
\(\ds \) \(=\) \(\ds 3 \frac 5 7\)
\(\ds \leadsto \ \ \) \(\ds b\) \(=\) \(\ds 4 \times \frac {26} 7 - 10\)
\(\ds \) \(=\) \(\ds \frac {104 - 70} 7\)
\(\ds \) \(=\) \(\ds \frac {34} 7\)
\(\ds \) \(=\) \(\ds 4 \frac 6 7\)

So:

$A$ is $3 \frac 5 7$
$B$ is $4 \frac 6 7$.

$\blacksquare$


Source of Name

This entry was named for Metrodorus.


Sources