n(b) = b
s = merah + hijau + kuning + biru
s = 15 + 14 + 13 + b
s = 42 + b
P(b) = n(b) / s
8/29 = b / (42 + b)
8 x (42 + b) = b x 29
8b + 336 = 29b
21b = 336
b = 336 / 21
b = 16
P(hijau) = n(hijau) / s
= 14 / (15 + 14 + 13 + b)
= 14 / (15 + 14 + 13 + 16)
= 14 / 58