from elementary and high school(s)

Question

(1a) Most of the students in the chess club come from elementary and high schools.

(1b) Most of the students in the chess club come from elementary and high school.

(2a) Most of the students he tutors are in elementary and high schools.

(2b) Most of the students he tutors are in elementary and high school.

The word, school, is both uncountable and countable. I am not sure whether I should use the singular or plural form.

Answer 1

1. Assuming that the club members come from several different schools, I would expect the plural.

2. You could use the singular here as it refers to the students' educational level rather than the actual school thy attend.