Database: theme_gallery

Question: Show the theme for exhibitions with both records of an attendance below 100 and above 500.
SQL: SELECT T2.theme FROM exhibition_record AS T1 JOIN exhibition AS T2 ON T1.exhibition_id  =  T2.exhibition_id WHERE T1.attendance  <  100 INTERSECT SELECT T2.theme FROM exhibition_record AS T1 JOIN exhibition AS T2 ON T1.exhibition_id  =  T2.exhibition_id WHERE T1.attendance  >  500

Question: How many exhibitions have a attendance more than 100 or have a ticket price below 10?
SQL: SELECT count(*) FROM exhibition_record AS T1 JOIN exhibition AS T2 ON T1.exhibition_id  =  T2.exhibition_id WHERE T1.attendance  >  100 OR T2.ticket_price  <  10