Student(snum: integer, sname: string, major: string, level: string, age: integer) Class(name: string, meets at: string, room: string, fid: integer) Enrolled(snum: integer, cname: string) Faculty(fid: integer, fname: string, deptid: integer) The meaning of these relations is straightforward; for example, Enrolled has one record per student-class pair such that the student is enrolled in the class. Write the following queries in relational algebra NOT SQL. No duplicates should be printed in any of the answers. 9. For each faculty member that has taught classes only in room R128, print the faculty members name and the total number of classes she or he has taught. 10. Find the names of students enrolled in the maximum number of classes. 11. Find the names of students not enrolled in any class. 12. For each age value that appears in Students, find the level value that appears most often. For example, if there are more FR level students aged 18 than SR, JR, or SO students aged 18, you should print the pair (18, FR).