Greek Anthology Book XIV: Metrodorus: 129

Arithmetical Epigram of Metrodorus
A traveller, ploughing with his ship the broad gulf of the Adriatic, said to the captain, "How much sea have we still to traverse?" And he answered him, "Voyager, between Cretan Ram's Head and Sicilian Peloris are six thousand stades, and twice two-fifths of the distance we have traversed remains till the Sicilian strait.

Solution
It is assumed that "Sicilian Peloris" and "the Sicilian strait" are the same place.

That is, the total distance is $6000$.

Let $d$ be the distance left to travel.

Hence:

So the narrator has $2666 \frac 2 3$ remaining to travel.

He has already travelled $3333 \frac 1 3$.