Key Facts

Part of Basic Probability · Section 2 of 7

Key FactsUnit: ProbabilityGCSE

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.

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

Practice questions for Basic Probability

Which value represents an impossible event on a probability scale?

  • A. 0
  • B. 0.5
  • C. 1
  • D. 2
1 markfoundation

Explain what is meant by theoretical probability and state the formula used to calculate it.

2 marksstandard

Quick recall flashcards

Can probability be negative?
No, probability must be between 0 and 1
What is probability?
A measure of how likely an event is to occur, expressed as a number between 0 and 1

13 questions on Basic Probability — practise free

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