CREATE TABLE table_25046766_1 (episode_no VARCHAR, written_by VARCHAR)

When don inglis and ralph smart are the writers how many episode numbers are there?
SELECT COUNT(episode_no) FROM table_25046766_1 WHERE written_by = "Don Inglis and Ralph Smart"
SELECT COUNT("episode_no") FROM "table_25046766_1" WHERE "Don Inglis and Ralph Smart" = "written_by"