This battle is significant in that the 4,000 Mexican soldiers are greatly outnumbered by the well-equipped French army that had not been defeated for almost 50 years.
What is the troop strength of the French army?
5,000
6,000
7,000
8,000
The battle in question is Battle of Puebla on 5th May 1862. Actually, many sources say that the number of French soldiers was 6,500 - so between 6 and 7 thousand! However, I think that the safer option is 6000 as many other sources say "just above 6000".