## Chapter 5 - Probability

**Prescribed Learning Outcomes:**

C1 – Interpret and assess the validity of odds and probability statements.

C2 – Solve problems that involve the probability of mutually exclusive and non-mutually exclusive events.

C3 – Solve problems that involve the probability of two events.

## 5.1/5.2 - Probability and Odds

Probability and odds are related but significantly different.

Probability uses the number of outcomes you are interested in with the number of total possible outcomes while odds uses the number of outcomes you are interested in with the number outcomes you are not interested in (which, together, are the total).

Please watch the probability and odds video.

Please do 5.1 page 303 #2,3 and 5.2 page 310 #4-18.

Probability uses the number of outcomes you are interested in with the number of total possible outcomes while odds uses the number of outcomes you are interested in with the number outcomes you are not interested in (which, together, are the total).

Please watch the probability and odds video.

Please do 5.1 page 303 #2,3 and 5.2 page 310 #4-18.

## 5.3 - Probabilities Using Counting Methods

To calculate probability use the number of outcomes that you are interested in divided by the total number of possible outcomes.

Sometimes calculating the number of outcomes you are interested in and the total number of possible outcomes can be difficult unless you use the fundamental counting principle, permutations or combinations. This section will show how to use these to calculate probabilities.

Please watch the probabilities using counting methods video.

Please do 5.3 page 321 #4-17.

Sometimes calculating the number of outcomes you are interested in and the total number of possible outcomes can be difficult unless you use the fundamental counting principle, permutations or combinations. This section will show how to use these to calculate probabilities.

Please watch the probabilities using counting methods video.

Please do 5.3 page 321 #4-17.

## 5.4 - Mutually Exclusive Events

Mutually exclusive events are two or more events that do not share any outcomes. This section looks at how calculating probabilities for mutually exclusive events is slightly different from calculating probabilities for events that are not mutually exclusive.

Please watch the mutually exclusive events video.

Please do 5.4 page 338 #4-9, 12-16.

When you have finished this, please read the Monty Hall puzzle on page 341 and discuss it with your classmates. When you think you have a solution, please discuss it with Mrs. Buck.

Please watch the mutually exclusive events video.

Please do 5.4 page 338 #4-9, 12-16.

When you have finished this, please read the Monty Hall puzzle on page 341 and discuss it with your classmates. When you think you have a solution, please discuss it with Mrs. Buck.

## 5.5 - Conditional Probability

Conditional probability is a difficult concept because you have to consider the probability of events that have already happened. Conditional probability occurs when one event happening changes the probability of the following events.

For example, if you pull a card from the deck and do not replace it, you change the probability of the next card that you are going to pull because now there are only 51 cards in the deck. If, however, you replace the first card before selecting the second then you do not have a need for conditional probability.

Conditional probability is used any time the conditions for each event is not EXACTLY the same as previous events.

Please watch the conditional probability video.

Please do 5.5 page 350 #4-10.

For example, if you pull a card from the deck and do not replace it, you change the probability of the next card that you are going to pull because now there are only 51 cards in the deck. If, however, you replace the first card before selecting the second then you do not have a need for conditional probability.

Conditional probability is used any time the conditions for each event is not EXACTLY the same as previous events.

Please watch the conditional probability video.

Please do 5.5 page 350 #4-10.

## 5.6 - Independent Events

Independent events are a little easier to understand because, if you want to know the probability of more than one independent event, you just multiply the probabilities for each event together.

This section shows using a tree diagram to solve more problems.

Please watch the independent events video.

Please do 5.6 page 360 #4-13.

This section shows using a tree diagram to solve more problems.

Please watch the independent events video.

Please do 5.6 page 360 #4-13.