This key facts covers Key Facts within Basic Probability for GCSE Mathematics. Revise Basic Probability in Probability for GCSE Mathematics with 13 exam-style questions and 20 flashcards. This topic appears regularly enough that it should still be part of a steady revision cycle. It is section 2 of 7 in this topic. Use this key facts to connect the idea to the wider topic before moving on to questions and flashcards.
Topic position
Section 2 of 7
Practice
13 questions
Recall
20 flashcards
Key Facts
- Probability = number of successful outcomes ÷ total number of possible outcomes
- Probability is always between 0 and 1 (or 0% and 100%)
- P = 0 means the event is impossible
- P = 1 means the event is certain
- P = 0.5 means the event is equally likely to happen or not happen
- All probabilities for all possible outcomes must add up to 1
Keep building this topic
Read this section alongside the surrounding pages in Basic Probability. That gives you the full topic sequence instead of a single isolated revision point.
Practice Questions for Basic Probability
Which value represents an impossible event on a probability scale?
Explain what is meant by theoretical probability and state the formula used to calculate it.
Quick Recall Flashcards
13 questions on Basic Probability — practise free
Instant marking, adaptive difficulty, and 20 spaced repetition flashcards. Free until your GCSEs.
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