Report all majors.
select distinct major from student
How many have 3 students or more?
select count(*) from (select major from student group by major having count(*) >= 3)
How many have less than 3 students?
select count(*) from (select major from student group by major having count(*) < 3)
Report those majors with less than 3 students.
select major from student group by major having count(*) < 3