show the name and capacity of all dorms.
select dorm_name, student_capacity from dorm
find the name of the dorm with the largest capacity.
select dorm_name from dorm order by student_capacity desc limit 1
how many students are living in there?
select count(*) from student as t1 join lives_in as t2 on t1.stuid = t2.stuid join dorm as t3 on t3.dormid = t2.dormid where t3.student_capacity = (select max(student_capacity) from dorm)
what is the average age of these students?
select avg(t1.age) from student as t1 join lives_in as t2 on t1.stuid = t2.stuid join dorm as t3 on t3.dormid = t2.dormid where t3.student_capacity = (select max(student_capacity) from dorm)