CREATE TABLE table_24399615_4 (viewers VARCHAR, bbc_three_weekly_ranking VARCHAR)

How many items are listed under viewers column when the bbd three weekly ranking was 1?
SELECT COUNT(viewers) FROM table_24399615_4 WHERE bbc_three_weekly_ranking = "1"
SELECT COUNT("viewers") FROM "table_24399615_4" WHERE "1" = "bbc_three_weekly_ranking"