🎲 GCSE Probability
Master the mathematics of chance with free exam-style questions and worked solutions. From basic probability to tree diagrams and conditional probability.
What is GCSE Probability?
Probability measures how likely events are to happen, expressed as a number between 0 (impossible) and 1 (certain). It's used in weather forecasting, insurance, games, and countless real-world applications.
- Basic probability – calculating simple probabilities as fractions
- Combined events – AND rule (multiply), OR rule (add)
- Tree diagrams – visualising sequences of events
- Venn diagrams – representing overlapping sets
- Conditional probability – when outcomes affect each other
📚 Probability Topics
🎯 Basic Probability
Calculate simple probabilities. Understand the probability scale and notation.
🌳 Tree Diagrams
Draw and use tree diagrams to calculate probabilities of combined events.
⭕ Venn Diagrams
Use Venn diagrams to represent sets and calculate probabilities.
🔗 Combined Events (AND/OR)
Apply the AND rule (multiply) and OR rule (add) for combined events.
📊 Conditional Probability
Calculate probability when one event affects another. Without replacement problems.
💡 Probability Tips
AND = Multiply: P(A and B) = P(A) × P(B) for independent events.
OR = Add: P(A or B) = P(A) + P(B) for mutually exclusive events.
Draw tree diagrams: They make complex probability problems much easier to visualise.
Check your answer: All probabilities must be between 0 and 1!