Question

Bob Bluster, the KNEWS meteorologist, determined that the mathematical odds of $\emph{no rain}$ tomorrow are 11:9. What would a mathematics student determine as the percent chance there $\emph{will be rain}$ tomorrow? (If the odds of an event happening are $a:b$, then the probability that it occurs is $\frac{a}{a + b}$.)

Answer 1

Answer:

45% chance there will be rain tomorrow.

Step-by-step explanation:

A probability is the number of desired outcomes divided by the number of total outcomes.

11:9 odds that there will be no rain

In 11+9 = 20 experiments, in 11 there will be no rain and 9 there will be rain.

Percent change there is rain:

Desired outcomes:

9 experiments(rain)

Total outcomes:

20 experiments

Probability

$p = \frac{9}{20} = 0.45$

45% chance there will be rain tomorrow.