Three tennis players, Serena, Maria, and Simona, are playing in a tournament according to the following rules: two of them are chosen at random and play against each other

Three tennis players, Serena, Maria, and Simona, are playing in a tournament according to the following rules: two of them are chosen at random and play against each other. The winner of the match plays against the remaining player and the winner of the second match wins the tournament. Because players have met before there is historic information about probability of winning: Serena has a 4 to 1 odds of winning against Maria and a 9 to 2 odds of winning against Simona. Maria has a 3 to 2 odds of winning against Simona.
a. What is the probability that Simona will win the tournament if the first match is Serena versus Maria?
b. What is the probability that Simona will win the tournament if the first match is Simona versus Maria?
c. What is the probability that Simona will win the tournament?