the probability of horse C winning = x
the probability of horse B winning = 2x
the probability of horse A winning = 4x
Total probability of winning is 1
So P(A) + P(B) + P(C) = 1
—> x + 2x + 4x = 1 —> x = 1/7
The probability of winning of horses A, B, and C are 4/7, 2/7, and 1/7