Using this relation:

Student(snum: integer, sname: string, major: string, level: string, age: integer) Class(name: string, meets_at: time, room: string, fid: integer) Enrolled(snum: integer, cname: string) Faculty(fid: integer, fnarne: string, deptid: integer)

Write the following queries in relational algebra:

Find the names of students enrolled in the maximum number of classes.

Find the names of students not enrolled in any class.

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).