A seventh grade and eighth grade student problem

[K Sengupta]

Seventh- and eighth-grade students participated in a tournament. Each contestant played each other contestant once. There were ten times as many eighth-grade students, but they were able to win only four-and-a-half times as many points as seventh graders.

How many seventh-grade students participated, and how many points did they collect?

Note: Assume one point for every win, and no drawn outcomes.

 

[skeptic2]

Spoiler:There were 2 seventh graders who had 4 wins and 20 eighth graders who had 18 wins.