One container contains 6 red and 4 white balls, while a second container contains 7 red and 3 white balls. A ball is chosen at random from the first container and placed in the second.
Then a ball is chosen at random from the second container and placed in first.
What is the probability to choose a red ball of the second container
What is the probability the ball was red chosen from the first container if
know that from the second selected white