Well done, you scored out of 10. As a reward for completing the quiz, meet Harry, Hermione, Ron, Genny, Luna and Neville, one of our favourite pets!
Bad Luck, you only scored out of 10. But as a reward for completing the quiz, meet Harry, Hermione, Ron, Genny, Luna and Neville, one of our favourite pets!
Build GCSE probability skills: outcomes, probabilities, and fair games. Understand equally likely events, sample space, and experimental probability using frequencies.
Explore the Topic →
(quiz starts below)
Fascinating Fact:
For a fair game, all outcomes must be equally likely. A biased coin breaks this, so observed long run frequencies will not match 1/2 and 1/2.
In GCSE Maths, probability helps you predict and compare chances. You’ll list sample spaces, use fractions/decimals/percentages for probabilities, spot fair or biased situations, and estimate chances from real-life frequency data.
Key Terms
Outcome: A single possible result of an experiment, such as “heads” on a coin toss.
Sample space: The complete list of all possible outcomes, e.g., {heads, tails}.
Relative (experimental) frequency: An estimate of probability found from data: number of successes ÷ total trials.
Frequently Asked Questions (Click to see answers)
What does “equally likely” mean in probability?
“Equally likely” means each outcome has the same chance. For a fair coin there are two outcomes, so each has probability 1/2.
How do I calculate the probability of an event?
Use favourable outcomes ÷ total outcomes. Simplify the fraction or write it as a decimal or percentage.
What is experimental probability?
It’s a probability estimated from data: successes ÷ trials. With more trials, it usually gets closer to the theoretical probability.