CREATE TABLE table_24319661_5 (no_in_series INT, us_viewers__million_ VARCHAR)

What episode number in the series had 2.77 million U.S. viewers?
SELECT MAX(no_in_series) FROM table_24319661_5 WHERE us_viewers__million_ = "2.77"
SELECT MAX("no_in_series") FROM "table_24319661_5" WHERE "2.77" = "us_viewers__million_"