What are the locations that have both tracks with more than 90000 seats, and tracks with fewer than 70000 seats?
SELECT LOCATION FROM track WHERE seating  >  90000 INTERSECT SELECT LOCATION FROM track WHERE seating  <  70000
locations that have both = INTERSECT; tracks with more than 90000 seats refers to seating > 90000; tracks with fewer than 70000 seats refers to seating < 70000;