Now, I solve the problem for the second race.

Looking at the problem, I write the ratio of probabilities, noting the probability of each animal to win with the corresponding initial:

E/R = 2
E/H = 1/2

So, the probabilities for each animal to win are:

Hippopotamus -- 4x
Elephant --2x
Rhinoceros --x

The total is 7x.

The odds for the hippopotamus are: 3 to 4 against and 4 to 3 to win
The odds for the elephant are: 5 to 2 against and 2 to 5 to win
The odds for the rhinoceros are: 6 to 1 against and 1 to 6 to win