Question

how many subjects does this site have?

Answer 1

@danielle02 I think admins would know that, we have many official subjects and some unofficial subjects. Just click on "Find more Subjects" on the top of the page and you'd find many subjects.
If you can't find the subject of your choice, do suggest in OpenStudy feedback for new subject(s). Admins would consider your opinion and we might get a new subject.
Thanks :)

Answer 2

Back in the day, users could create groups. There are COUNTLESS number of groups that are still getting deleted.

There are 35 official subjects in total.

Answer 3

\[\frac{ \left( n \right) \left( n-1 \right)}{ 2 }\]