question: What is the number of viewers in millions for the episode on October 10, 2008, and a Channel 4 weekly rank a smaller than 30?
answer: SELECT COUNT(viewers__millions_) FROM table_name_94 WHERE airdate = "october 10, 2008" AND channel_4_weekly_rank_a < 30
context: CREATE TABLE table_name_94 (viewers__millions_ VARCHAR, airdate VARCHAR, channel_4_weekly_rank_a VARCHAR)