Find the locations where have both tracks with more than 90000 seats and tracks with less than 70000 seats.
SELECT LOCATION FROM track WHERE seating  >  90000 INTERSECT SELECT LOCATION FROM track WHERE seating  <  70000
locations where have both tracks with more than 90000 seats and tracks with less than 70000 seats refers to the use of INTERSECT between two conditions: seating > 90000 and seating < 70000;