What's the age of the student named Derek?
select age from student where fname = "Derek"
Tell me the age of students in the club "Bootup Baltimore"?
select age from club as t1 join member_of_club as t2 on t1.clubid = t2.clubid join student as t3 on t2.stuid = t3.stuid where t1.clubname = "Bootup Baltimore"
How many members of that club are younger than 18?
select count(*) from club as t1 join member_of_club as t2 on t1.clubid = t2.clubid join student as t3 on t2.stuid = t3.stuid where t1.clubname = "Bootup Baltimore" and t3.age < 18