Greek Anthology Book XIV: Metrodorus: 143

Arithmetical Epigram of Metrodorus
The father perished in the shoals of the Syrtis, and this, the eldest of the brothers, came back from that voyage with five talents. To me he gave twice two-thirds of his share, on our mother he bestowed two-eighths of my share, nor did he sin against divine justice.

Solution
Let $a$ be the elder brother's share.

Let $b$ be the narrator's share.

Let $c$ be the mother's share.

We have:

So:
 * the elder brother takes $1 \frac 7 8$


 * the narrator takes $2 \frac 1 2$


 * the mother takes $\dfrac 5 8$ of a.