database system assignment help will thumbs up for the correct answer ASAPConsider the following relations:

Course (cid:string, cname: string, dept: string)

Student (sid: integer, sname: string, gpa: string, dept: string)

Enroll (sid: integer, cid: string, grade: string)  

The meaning of these relations is straightforward and the keys are underlined. Write the following queries in SQL. 

a. Find the number of students not enrolled in any class.

b. List each student's name, along with the number of courses registered by that student.

c. Find name of students in 'Math' department who took all the courses offered by 'Computer Science' department.