I need these solutions in 3 hours.
I've 2 boxes. THe first box has 2 new and 3 old balls. The second box has 3 new and 4 old balls. I took one ball from the first box and put it into the second box. Now I take the ball from the second box.
What's the probability that:
1) The ball taken from the second box is new.
2) The ball taken from the first box was new if I know that the ball taken from the second box was old.