Final answer:
The exact number of Greek troops on the last day of battle is not specified, but the Greek coalition led by Spartans and Athenians was significant enough to achieve victory over the Persians. Previous confrontations mentioned fielded thousands of Greek warriors from various city-states.
Step-by-step explanation:
The total number of Greek troops fighting on the last day of the significant battle in question is not explicitly provided within the given text.
However, a decisive battle in 479 BCE involved a Greek coalition led by the Spartans and another naval battle led by the Athenians.
It is implied that this coalition was substantial enough to confront and eventually defeat a large Persian army. In prior battles, such as the Battle of Marathon in 490 BCE, the Athenians had fielded 10,000 hoplites, and in 480 BCE, roughly 6% of the Greek cities joined the defensive coalition created by Athens and Sparta against a massive Persian force. While exact numbers are not detailed for the very last battle, it is clear the Greeks managed to amass a formidable force combining the strength of various poleis to repel the Persian invasion.