Let the total games = 12 + 2 + 1 + 3m = 15 + 3m where m is the number of weeks after the fifth one
And the number of wins = 2 + 2m
So we wish that
[2 + 2m ] / [ 15 + 3m ] = .50
2 + 2m = .50 [ 15 + 3m ]
2 + 2m = 7.5 + 1.5m
2m - 1.5m = 7.5 - 2
.5m = 5.5
m = 5.5 / .5 = 11 weeks after the 5th one
So....you actually need to play 16 weeks
