Consider the following schema: Emp(eno,ename,ph_no,address,salary,dno) Department(dno,dname,location) Project(pno, dno,status) Works_On(eno,pno,hours) Solve the following queries using Relational Algebra operations a. List eno and dno from Emp where dno as ’20’ b. List eno,ename,dno,dname from Emp and Department. c. List eno,ename,pno from Emp and ...