ANSWER

Step-by-step explanation
(a) To find the odds in favor of Alonzo winning a medium stuffed animal, we have to divide the probability that he will win a medium stuffed animal by the probability that he will not win a medium stuffed animal.
There are 5 medium balloons out of 12 balloons in total, so, the probability that he will win a medium stuffed animal is:

And the probability that he will not win a medium stuffed animal is:

Therefore, the odds in favor of Alonzo winning a medium stuffed animal is:

In other words, the odds are 5 to 7.
(b) To find the odds against Alonzo winning a medium stuffed animal, we have to find the inverse of the odds of him winning or divide the probability that he will not win a medium stuffed animal by the probability that he will win a medium stuffed animal:

In other words, the odds are 7 to 5.