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_20971444_3 ( rank__timeslot_ VARCHAR, rating__18_49_ VARCHAR )

### Question ###
Name the total number of rank timeslot for 18-49 being 3.1

### Accurate SQL ###

SELECT COUNT(rank__timeslot_) FROM table_20971444_3 WHERE rating__18_49_ = "3.1"