–1 votes –1 votes PLEASE EXPLAIN WHEATHER IT WOULD BE SOME EC DEPARMENT OR ALL EC DEPARTMENT I THINK ALL BECOZ IT IS SELECTION EID OF STUDENT WHO HAVE NOT ENROLLED IN ANY COURSE OF EC Databases databases relational-algebra made-easy-test-series + – Himanshu Kashyap asked Jan 12, 2019 • edited Mar 4, 2019 by ajaysoni1924 Himanshu Kashyap 667 views answer comment Share Follow See all 6 Comments See all 6 6 Comments reply Show 3 previous comments Himanshu Kashyap commented Jan 12, 2019 reply Follow Share How A is correct it is saying some of the course of the Ec which means it will the output if some student have taken some ec and some not ec It should be like which dont have taken all the Ec course Please correct me i am confuse with some and all 0 votes 0 votes jatin khachane 1 commented Jan 12, 2019 reply Follow Share @Ayush Upadhyaya its D then ? 0 votes 0 votes Ayush Upadhyaya commented Jan 12, 2019 reply Follow Share Consider four classes of students Class A-Who take only CS courses and no student here has taken even a single EC course. Class B-WHo Take only EC courses Class C-Who take Some Cs course and Some EC course both at same time. Class D-Who have taken some cs courses and all ec courses. Final result set will include only students from class A. 1 votes 1 votes Please log in or register to add a comment.