CREATE TABLE table_15846 ("Order Year" CLOB, "Manufacturer" CLOB, "Model" CLOB, "Fleet Series  ( Quantity ) " CLOB, "Powertrain  ( Engine/Transmission ) " CLOB, "Fuel Propulsion" CLOB)

what is the fuel propulsion where the fleet series (quantity) is 310-329 (20)?
SELECT "Fuel Propulsion" FROM table_15846 WHERE "Fleet Series (Quantity)" = '310-329 (20)'
SELECT "Fuel Propulsion" FROM "table_15846" WHERE "Fleet Series (Quantity)" = '310-329 (20)'