Greek Anthology Book XIV: 147

Epigram

 * Answer of Homer to Hesiod when he asked the Number of the Greeks who took part in the War against Troy


 * There were seven hearths of fierce fire, and in each were fifty spits and fifty joints on them.


 * About each joint were nine hundred Achaeans.

Solution
Let $n$ be the number of Achaeans (that is, Greeks).

So there were $315 \, 000$ Achaeans in total.