The Mustangs have won 4 games and lost in 6.
Then, the probability for winning is 4/10............(1)
The probability of not winning is 6/10
In order to the Mustang to win 6 games, we need to find the number of games the mustang must play in order to won 6 games.
Let the number of games the Mustangs must play be x.
Then the chances to win in 6 games out of the x games must verify the probability mentioned above in (1) which is 4/10
Then, 6/x = 4/10
Now we will cross multiply to find x.
==> 4x = 6*10
==> 4X = 60
==> X = 15
Then, the Mustangs must play 15 games in order to win 6.