# Calculate probabilities of independent events

In this lesson, we will learn how to calculate probabilities of outcomes for independent events from tree diagrams

#### Unit quizzes are being retired in August 2023

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Quiz:

# Intro quiz - Recap from previous lesson

Before we start this lesson, let’s see what you can remember from this topic. Here’s a quick quiz!

Q1.Here is the first branch of a probability tree diagram.

1/3

Q2.Here is the first branch of a different probability tree diagram. What should the missing probability be?

2/3

Q3.This tree diagram shows Amir taking red and blue counters from a jar. He replaces the counter after he has picked one up.

3/3

#### Unit quizzes are being retired in August 2023

Why we're removing unit quizzes from the website >
Quiz:

# Intro quiz - Recap from previous lesson

Before we start this lesson, let’s see what you can remember from this topic. Here’s a quick quiz!

Q1.Here is the first branch of a probability tree diagram.

1/3

Q2.Here is the first branch of a different probability tree diagram. What should the missing probability be?

2/3

Q3.This tree diagram shows Amir taking red and blue counters from a jar. He replaces the counter after he has picked one up.

3/3

# Video

Click on the play button to start the video. If your teacher asks you to pause the video and look at the worksheet you should:

• Click "Close Video"
• Click "Next" to view the activity

Your video will re-appear on the next page, and will stay paused in the right place.

# Worksheet

These slides will take you through some tasks for the lesson. If you need to re-play the video, click the ‘Resume Video’ icon. If you are asked to add answers to the slides, first download or print out the worksheet. Once you have finished all the tasks, click ‘Next’ below.

#### Unit quizzes are being retired in August 2023

Why we're removing unit quizzes from the website >
Quiz:

# Calculate probabilities of independent events

Don’t worry if you get a question wrong! Forgetting is an important step in learning. We will recap next lesson.

Q1.For the probability tree shown, which calculation will find the probability of red followed by blue happening?

1/3

Q2.The probability that Amy and Joe win a game of chess is shown in the tree diagram. Work out the probability that over 2 games Amy wins twice.

2/3

Q3.James draws this probability tree diagram to help him calculate probabilities of taking sweets from a bag. What assumptions has James made when completing this probability tree?

3/3

#### Unit quizzes are being retired in August 2023

Why we're removing unit quizzes from the website >
Quiz:

# Calculate probabilities of independent events

Don’t worry if you get a question wrong! Forgetting is an important step in learning. We will recap next lesson.

Q1.For the probability tree shown, which calculation will find the probability of red followed by blue happening?

1/3

Q2.The probability that Amy and Joe win a game of chess is shown in the tree diagram. Work out the probability that over 2 games Amy wins twice.

2/3

Q3.James draws this probability tree diagram to help him calculate probabilities of taking sweets from a bag. What assumptions has James made when completing this probability tree?

3/3

# Lesson summary: Calculate probabilities of independent events

## Time to move!

Did you know that exercise helps your concentration and ability to learn?

For 5 mins...

Move around:
Climb stairs

On the spot:
Chair yoga