CREATE TABLE table_6427 ("Make/ Model" TEXT, "length" TEXT, "Year" FLOAT, "Numbers  ( Quantity Ordered ) " TEXT, "Fuel Propulsion" TEXT)

Which Fuel Propulsion has Numbers (Quantity Ordered) of 7124-7156 (33 buses)?
SELECT "Fuel Propulsion" FROM table_6427 WHERE "Numbers (Quantity Ordered)" = '7124-7156 (33 buses)'
SELECT "Fuel Propulsion" FROM "table_6427" WHERE "Numbers (Quantity Ordered)" = '7124-7156 (33 buses)'