## Thinking Mathematically (6th Edition)

The odds against E are found by taking the probability that E will not occur and dividing by the probability that E will occur. Odds against E = $\frac{P(not E)}{P(E)}$ We find the odds that you will win a boat if you purchased 20 out of 1000 raffle tickets. P(E) = $\frac{20}{1000}$ = $\frac{1}{50}$ P(not E)= 1- P(E) =1 - $\frac{1}{50}$ =$\frac{50 - 1}{50}$ =$\frac{49}{50}$ Odds against E = $\frac{\frac{49}{50}}{\frac{1}{50}}$ = $\frac{49}{1}$