## Thinking Mathematically (6th Edition)

The odds in favor of E are found by taking the probability that E will occur and dividing by the probability that E will not occur. Odds in Favor = $\frac{P(E)}{P(not E)}$ Using the information given to us in the problem, we find the odds in favor of selecting a tragedy or a history. E: {10 histories, 10 tragedies} P(E)= $\frac{20}{38}$ = $\frac{10}{19}$ P(not E) = 1 - P(E) = 1 - $\frac{10}{19}$ =$\frac{19 - 10}{19}$ = $\frac{9}{19}$ Odds in Favor = $\frac{\frac{10}{19}}{\frac{9}{19}}$ = $\frac{10}{9}$