задание

For each type of book, list the type and average price, consider only paperback books for those
types for which the average price is less than $10.

таблица

CREATE TABLE book (
book_code CHAR(4),
title CHAR(40),
publisher_code CHAR(3),
type CHAR(3),
price DECIMAL(4,2),
paperback CHAR(1),
PRIMARY KEY (book_code),
FOREIGN KEY (publisher_code) REFERENCES publisher
);

что то не получаеться