One integer A after another is added to 12.
Then integers as 12, 12 + A, 12 + A + A, -------- are coming out.
When these numbers is rounded off at ones digit, it will become at order 10, x, 40, 50, 70, y -------.
Answer to the following questions.
(1) Find A.
(2) Find the number filled in x and y.