I thought I knew how to do this but I don't

ANSWER
[tex]\begin{gathered} (a)\frac{5}{7} \\ (b)\frac{7}{5} \end{gathered}[/tex]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:
[tex]P(win)=\frac{5}{12}[/tex]And the probability that he will not win a medium stuffed animal is:
[tex]P(not-win)=1-\frac{5}{12}=\frac{7}{12}[/tex]Therefore, the odds in favor of Alonzo winning a medium stuffed animal is:
[tex]\begin{gathered} \frac{\frac{5}{12}}{\frac{7}{12}}=\frac{5}{12}\cdot\frac{12}{7} \\ \Rightarrow\frac{5}{7} \end{gathered}[/tex]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:
[tex]\begin{gathered} \frac{\frac{7}{12}}{\frac{5}{12}}=\frac{7}{12}\cdot\frac{12}{5} \\ \Rightarrow\frac{7}{5} \end{gathered}[/tex]In other words, the odds are 7 to 5.