Answer:
The competition can be played in 7 different ways
Step-by-step explanation:
First game : X
Second game : Y
Third game : Y
After that either X or Y can win
The competition ends with Y winning as he/she won 3 games in a row
more games are required to decide the winner
more games are required to decide the winner
The competition ends with X winning as he/she won 3 games in a row
The competition ends after the seventh game. Whoever wins seventh game wins the competition as he/she would've won 4 games in total by then.
more games are required to decide the winner
The competition ends with Y winning as he/she won 4 games in total
The competition ends after the seventh game. Whoever wins seventh game wins the competition as he/she would've won 4 games in total by then.
∴The competition can be played in 7 different ways