Common Data for Questions 74 and 75: Consider the following relational schema.…

GATE · 2008 · IT

Common Data for Questions 74 and 75: Consider the following relational schema.

Consider The Following Relational Scheme

Student (school-id, sch-roll-no, sname, saddress)

School (school-id, sch-name, sch-address, sch-phone)

Enrolment (school-id, sch-roll-no, erollno, examname)

ExamResult (Erollno, examname, marks)

Consider the following tuple relational calculus query

{ t | ∃E ∈ Enrolment: t = E.school-id ∧ ( |{ x | x ∈ Enrolment ∧ x.school-id = t ∧ (∃B ∈ ExamResult: B.erollno = x.erollno ∧ B.examname = x.examname ∧ B.marks > 35) }| / |{ x | x ∈ Enrolment ∧ x.school-id = t }| ) × 100 > 35 }

If a student needs to score more than 35 marks to pass an exam what does the query return?

A.
The empty set
B.
Schools with more than 35% of it's student enrolled in some exam or the other
C.
Schools with a pass percentage above 35% over all exams taken together
D.
Schools with a pass percentage above 35% over each exam.

Attempted by 50 students.

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