GCSE Maths Probability: lesson and practice questions

By the end of this chapter you will be able to

• Use the probability scale from 0 to 1 and the language of chance, and write probabilities as fractions, decimals and percentages
• Calculate the theoretical probability of an event when outcomes are equally likely, and use P(not A) = 1 − P(A)
• Use relative frequency from experiments to estimate probabilities, find expected numbers, and judge whether something is fair or biased
• List outcomes systematically and use sample-space tables for two events
• Use the multiplication rule for independent events and the addition rule for mutually exclusive events
• Draw and use tree diagrams, with and without replacement
• Use sets, Venn diagrams, two-way tables and frequency trees to organise information and find probabilities

You should already know

• Fractions, decimals and percentages, and simplifying fractions (Chapters 3, 4 and 5)
• Multiplying and adding fractions (Chapter 3)
• Ratio and sharing in a ratio (Chapter 15)
• Solving linear equations (Chapter 9)

Where this leads

• Statistics: charts, averages and sampling (Chapter 24)
• Probability in real-life risk, games and insurance