Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_23117208_3 ( no_in_season INTEGER, no_in_series VARCHAR )

### Question ###
which is the biggest number of episode in the season, where the number of the episode in series is 20?

### Accurate SQL ###

SELECT MAX(no_in_season) FROM table_23117208_3 WHERE no_in_series = 20