You must be thinking of the battle at Thermopylae ... the Hot Gates.
Your answer reflects a certain amount of historical insight but your insight is a little myopic ... the three hundred Spartans who fought and died at Thermopylae in 480 BCE are not to be confused with the Spartans who marched out to confront Xenophon.
There are differing opinions as to exactly how many Persians King Xerxes had when he attacked Greece but I think we can safely say that there were more than a metric boat-load ... counting for inflation and the devaluation of the Dollar, that might be as many as 310,000 Persians ... the Greeks had three hundred Spartans and a few thousand Phokians and Lokrians but the Spartans took the forefront of the battle formation ... when the Persian onslaught became overwhelming, the Phokians and Lokrians withdrew and with two exceptions, the Spartans were all killed.
Three hundred Spartans against three hundred thousand Persians was not really a fair fight but if three hundred Spartans had marched out to confront Xenophon and his eight thousand mercenaries ... trust me ... Xenophon and his army would have run for their lives ... literally ... their lifespan would be in direct proportion to how fast they could run.
Go back to the Quiz and try to think like a Spartan ... if you’re not sure exactly what that means ... here’s a hint ... if you look like you’re ready for trouble, most troublemakers will leave you alone.