Student(sID, surName, firstName, campus, email, gpa)

Course(dept, cNum, name, breadth)

Offering(oID, dept, cNum, term, instructor)

Took(sID, oID, grade)

Offering[dept, cNum] ⊂ Course[dept, cNum]

Took[sID] ⊂ Student[sID]

Took[oID] ⊂ Offering[oID]

Q1: Student numbers of all students who took CSC343

$\Pi_{sID} \, (\sigma_{cNum=343 \land dept="CSC"} \, \text{Offering} \bowtie \text{Took})$

Q2: Student number of all students who took CSC343 and got A+

$Q2:=\Pi_{sID} \, (\sigma_{cNum=343 \land dept="CSC"} \, \text{Offering} \bowtie \sigma_{grade\ge 90}\text{Took})$

Q3: Names of all students from Q2

$\Pi_{firstName, surName} \, (\text{Q2} \bowtie \text{Student})$

Q5: sID of all students who have earned some grade ≥ 80 and some ≤ 50

$\Pi_{sID} \, (\sigma_{grade\le 50} \text{Took}) \cap \Pi_{sID} \, (\sigma_{grade\ge 80} \text{Took})$

$\Pi_{sID} \, ((\sigma_{grade \le 50} \text{Took}) \bowtie (\sigma_{grade \ge 80} \text{Took}) )$

Q7: Terms when either Cook or Pitassi was teaching CSC463

$\Pi_{term} \, (\sigma_{(dept = "CSC" \land cNum = 463) \land (instructor = "Cook" \lor instructor = "Pitassi")} \text{Offering})$