There are three similar boxes, containing(i). 6 black and 4 white balls(ii). 3 black and 7 white balls(iii). 5
black and 5 white balls, respectively. If you choose one of the three boxes at random and from that
particular box picks up a ball at random, and nd that to be black, what is the probability that the ball
picked up from the second box?
有三个类似的框，其中包含（i）。 6个黑球和4个白球（ii）。 3个黑球和7个白球（iii）。 5
黑色和5个白球。如果您随机选择三个框之一，