Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
### Context:
CREATE TABLE table_2226817_6 (no_in_series VARCHAR, original_air_date VARCHAR)
### Question:
How many series numbers do the episodes originally aired on October 28, 1990?
### Answer:
SELECT COUNT(no_in_series) FROM table_2226817_6 WHERE original_air_date = "October 28, 1990"