Question: What is the average age for each dorm and what are the names of each dorm?
SQL: SELECT avg(T1.age) ,  T3.dorm_name FROM student AS T1 JOIN lives_in AS T2 ON T1.stuid  =  T2.stuid JOIN dorm AS T3 ON T3.dormid  =  T2.dormid GROUP BY T3.dorm_name