5 Sophie and James are having a tennis competition. The winner of the competition is the first to win 2 matches in a row. If the competition has not been decided after 5 matches, then the player who has won more matches is declared the winner of the competition. For example, the following sequences are two ways in which Sophie could win the competition. (S represents a match won by Sophie; \(\mathbf { J }\) represents a match won by James.) \section*{SJSS SJSJS}

1. Explain why the sequence \(\mathbf { S S J }\) is not possible.
2. Write down the other three possible sequences in which Sophie wins the competition.
3. The probability that Sophie wins a match is 0.7 . Find the probability that she wins the competition in no more than 4 matches.