CREATE TABLE people (people_id DECIMAL, name TEXT, age DECIMAL, height DECIMAL, hometown TEXT)
CREATE TABLE gymnast (gymnast_id DECIMAL, floor_exercise_points DECIMAL, pommel_horse_points DECIMAL, rings_points DECIMAL, vault_points DECIMAL, parallel_bars_points DECIMAL, horizontal_bar_points DECIMAL, total_points DECIMAL)

From which hometowns did both people older than 23 and younger than 20 come from?
SELECT hometown FROM people WHERE age > 23 INTERSECT SELECT hometown FROM people WHERE age < 20
SELECT "hometown" FROM "people" WHERE "age" > 23 INTERSECT SELECT "hometown" FROM "people" WHERE "age" < 20