Sex-Linked Traits — Definition & Examples

You are in the very lucrative field of fruit fly breeding. You have a female fruit fly with red eyes, but you know that she has one X with the dominant red eye gene, and one X with the recessive white eye gene. You have a male fruit fly with white eyes, meaning he has one X with the white eye gene and a Y chromosome. The two flies have 200 children! 50% of the children are male. How many of the males have white eyes?