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_84 (quantity INTEGER, ptrd_nos VARCHAR)
### Question:
What is the highest Quantity for PTRD Nos. 3, 15?
### Answer:
SELECT MAX(quantity) FROM table_name_84 WHERE ptrd_nos = "3, 15"