CREATE TABLE table_40879 ("Week" FLOAT, "Date" TEXT, "Opponent" TEXT, "Result" TEXT, "Attendance" TEXT)

Which Opponent that has a Week larger than 3 on october 6, 1991?
SELECT "Opponent" FROM table_40879 WHERE "Week" > '3' AND "Date" = 'october 6, 1991'
SELECT "Opponent" FROM "table_40879" WHERE "Date" = 'october 6, 1991' AND "Week" > '3'