CREATE TABLE table_name_9 (district VARCHAR, city_area_km_2__ VARCHAR, serial_no VARCHAR)

What district was the city with an area smaller than 12 square kilometers and a serial number of 35?
SELECT district FROM table_name_9 WHERE city_area_km_2__ < 12 AND serial_no = 35
SELECT "district" FROM "table_name_9" WHERE "city_area_km_2__" < 12 AND "serial_no" = 35