SELECT COUNT("Total viewers") FROM table_28054 WHERE "Airdate" = '25 October 2012'
How many episodes aired on 25 october 2012?
CREATE TABLE table_28054 (
    "Episode no." real,
    "Airdate" text,
    "Dave Viewers" real,
    "Dave Rank" real,
    "Rank (cable)" real,
    "Dave ja vu Viewers" real,
    "Total viewers" real
)