text: 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_87 (quantity INTEGER, year_s__of_manufacture VARCHAR, seats VARCHAR)
  ### Question:
  What is the average quantity for coaches manufactured in 1921/23, and had 40 seats?
  ### Answer:
  SELECT AVG(quantity) FROM table_name_87 WHERE year_s__of_manufacture = "1921/23" AND seats = "40"