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_name_23 (points INTEGER, tyres VARCHAR, chassis VARCHAR)
### Question:
Tell me the average points with tyres of b and chassis of tf109
### Answer:
SELECT AVG(points) FROM table_name_23 WHERE tyres = "b" AND chassis = "tf109"