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 6 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 6
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