CREATE TABLE table_name_25 (opponent_number VARCHAR, site VARCHAR, date VARCHAR)

What is the Opponent name at memorial stadium minneapolis, mn on 10/20/1928?
SELECT opponent_number FROM table_name_25 WHERE site = "memorial stadium • minneapolis, mn" AND date = "10/20/1928"
SELECT "opponent_number" FROM "table_name_25" WHERE "10/20/1928" = "date" AND "memorial stadium • minneapolis, mn" = "site"