CREATE TABLE table_24399615_10 (episode_no VARCHAR2, bbc_three_weekly_ranking VARCHAR2, cable_rank VARCHAR2)

Which episode had bbc ranking and canle ranking of n/a?
SELECT COUNT(episode_no) FROM table_24399615_10 WHERE bbc_three_weekly_ranking = "N/A" AND cable_rank = "N/A"
SELECT COUNT("episode_no") FROM "table_24399615_10" WHERE "N/A" = "bbc_three_weekly_ranking" AND "N/A" = "cable_rank"