CREATE TABLE table_name_87 (tonnage INT, date VARCHAR, name_of_ship VARCHAR)

What was the average tonnage for Beatus, raided on 18 October 1940?
SELECT AVG(tonnage) FROM table_name_87 WHERE date = "18 october 1940" AND name_of_ship = "beatus"
SELECT AVG("tonnage") FROM "table_name_87" WHERE "18 october 1940" = "date" AND "beatus" = "name_of_ship"