How many different schools are there?
select count(*) from school
Which schools have school buses?
select t2.school from school_bus as t1 join school as t2 on t1.school_id = t2.school_id
Please also show the names of the drivers.
select t2.school, t3.name from school_bus as t1 join school as t2 on t1.school_id = t2.school_id join driver as t3 on t1.driver_id = t3.driver_id