From the tree diagram, the probability of winning the second set = 27 50 + 10 50 = 37 50. This means that in every 50 matches, she may win the second set 37 times (ie 37 becomes the denominator ...

First, represent the information on a tree diagram: From the tree diagram, the probability of winning the second set = 27 50 + 10 50 = 37 50.