Q3: Consider the University db with the tables:
Student (studno,name,hons,tutor,year)
Staff (lecturer,roomno)
Enrolled (studno,courseno,labmark,exammark)
Write queries in relational algebra that return the following:
1. The numbers of courses where a student had a better exam mark than lab mark.
2. The names of the lecturers who are tutoring a student who had an exam mark worse than the lab mark.
3. The names of the lecturers who are tutoring a 3rd year student.
4. The room numbers of the lecturers who are tutoring a 3rd year student.
5. The names of the lecturers who are tutoring more than one student
6. The names of the lecturers who are tutoring no more than one student