How many schools are there?
select count(*) from school
How many donations are there that are less than 8.5?
select count(*) from endowment where amount < 8.5
How many schools have more than one donator?
select count(*) from (select * from endowment group by school_id having count(*) > 1)
Among these schools, how many of them have more than one donator whose donation amount is less than 8.5?
select count(*) from (select * from endowment where amount < 8.5 group by school_id having count(*) > 1)