SELECT count(*) ,  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 WHERE T1.age  >  20 GROUP BY T3.dorm_name
Find the number of students who is older than 20 in each dorm.
SELECT count ( * ) , 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 WHERE T1.age > 20 GROUP BY T3.dorm_name
select count ( * ) , 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 where t1 . age > value group by t3 . dorm_name
Find the number of students who is older than 20 in each dorm .