Learning objective

Determine the probability of an event not occurring using the formula P(A′) = 1 - P(A), based on the probability of the event occurring.

Read the explanation, check the common trap, then practise with flashcards and questions.

Exam focus

Cambridge IGCSE StatisticsProbability

Study support

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Quick explanation

This point belongs to Probability, especially Probability outcomes.
You need to be able to determine the probability of an event not occurring using the formula P(A′) = 1 - P(A), based on the probability of the event occurring.
The key ideas to know are Calculate and Determine.
Use the linked flashcards and practice questions to check recall, then practise applying the idea in an exam-style answer.

Key concepts

CalculateDetermine

Why it matters

This objective helps connect Probability outcomes to exam-style questions, flashcards, and revision notes for Probability.

Revision tools

Flashcards10 linked cards

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Practice Questions7 linked questions

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0 of 5 attempted

Paper 1Statistical Techniques2 marks

Description

A bag contains 10 marbles: 4 red and 6 blue. A marble is drawn at random.

a
Calculate the probability of drawing a red marble.
Your answer
Aim for approximately 1 distinct marking point.
[1]
b
Calculate the probability of not drawing a red marble.
Your answer
Aim for approximately 1 distinct marking point.
[1]

Revision notestopic notes

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