Table: episodes_table_21
Columns: col
original_title
directed_by
written_by
original_airdate
prod_code
viewers

Question: When "helpful tracy" is the original title how many numbers are there?
SQL: SELECT COUNT("col") FROM episodes_table_21 WHERE "original_title" = '"Helpful Tracy"'

Question: When 1.12 is the production code what is the original title?
SQL: SELECT "original_title" FROM episodes_table_21 WHERE "prod_code" = '1.12'

Question: When "the postcard" is the original title what is the production code?
SQL: SELECT "prod_code" FROM episodes_table_21 WHERE "original_title" = '"The Postcard"'

Question: When 1.17 is the production code how many air dates are there?
SQL: SELECT COUNT("original_airdate") FROM episodes_table_21 WHERE "prod_code" = '1.17'