4. (20 points) Given that there are 2 inferior products out of 10, and 2 pieces are taken without replacement ("without replacement" means that each piece is NOT put back before the next piece is taken). Find the probability of the following events: (a) (5 points) Both pieces are genuine. (b) (5 points) Both pieces are inferior. (c) (5 points) One is a genuine product and one is an inferior product. (d) (5 points) The second piece is an inferior item.