CREATE TABLE table_name_31 (wins INT, position VARCHAR, f_laps VARCHAR)

What is the average wins with a 20th position and more than 0 f/laps?
SELECT AVG(wins) FROM table_name_31 WHERE position = "20th" AND f_laps > 0
SELECT AVG("wins") FROM "table_name_31" WHERE "20th" = "position" AND "f_laps" > 0