What are the maximum and minimum resolution of songs whose duration in 3 minutes?
SELECT max ( T2.resolution )  ,  min ( T2.resolution )  FROM files AS T1 JOIN song AS T2 ON T1.f_id   =   T2.f_id WHERE T1.duration LIKE "3:%"
maximum resolution refers to MAX(resolution); minimum resolution refers to MIN(resolution); songs whose duration is 3 minutes refers to duration LIKE '3:%';