CREATE TABLE table_name_15 (goals_against NUMBER, club VARCHAR2, points VARCHAR2)

Which Goals against have a Club of cd castell n, and Points smaller than 24?
SELECT AVG(goals_against) FROM table_name_15 WHERE club = "cd castellón" AND points < 24
SELECT AVG("goals_against") FROM "table_name_15" WHERE "cd castellón" = "club" AND "points" < 24