CREATE TABLE table_name_47 (wins NUMBER, class VARCHAR2, rank VARCHAR2)

Tell me the average wins for class of 50cc and rank of 8th
SELECT AVG(wins) FROM table_name_47 WHERE class = "50cc" AND rank = "8th"
SELECT AVG("wins") FROM "table_name_47" WHERE "50cc" = "class" AND "8th" = "rank"