CREATE TABLE table_27969432_3 (original_air_date VARCHAR, written_by VARCHAR)

How many episodes were written by david j. north & janet tamaro?
SELECT COUNT(original_air_date) FROM table_27969432_3 WHERE written_by = "David J. North & Janet Tamaro"
SELECT COUNT("original_air_date") FROM "table_27969432_3" WHERE "David J. North & Janet Tamaro" = "written_by"