need help with this two quieries.

students(sid,name,age,gpa) // sid is the primary key

courses(cid,deptid, description) // cid,deptid is the primary key

professors(ssn,name,address,phone,deptid) // ssn is the primary key

enrollment(sid,cid,section,grade) cid makes reference to the courses table. // sid, cid, and section is the primary key

teaches(cid,section,ssn). cid, section makes reference to the enrollment table // cid, section is the primary key

a. A list of those departments that offer more than 10 courses.

b. Produce a list of the name of those students whose professors name starts with an M. Your result must have no duplicates.