Given the following tables:

students(sid,name,age,gpa)

courses(cid,deptid, description)

professors(ssn,name,address,phone,deptid)

enrollment(sid,cid,section,grade). cid makes reference to the courses table.

teaches(cid,section,ssn). cid, section makes reference to the enrollment table

Provide SQL instructions for each of the following questions

4.List ssn and name of professors that work for the cs department, but are not teaching any cs courses.

5. List the number of courses offered by each department. Just the number of courses (not sections).

9.List of professors that work for departments with more than 20 faculty members and that offer more large sections than small and medium sections combined.