Key Concepts in Basic Probability
- Probability scale (0 to 1)
- P(event) = favourable outcomes / total outcomes
- Mutually exclusive events: P(A or B) = P(A) + P(B)
- Independent events: P(A and B) = P(A) × P(B)
- Expected frequency
Exam Tips for Basic Probability
- 💡Probabilities must sum to 1 for all mutually exclusive outcomes
- 💡P(not A) = 1 − P(A)
- 💡For "and" with independent events, multiply; for "or" with mutually exclusive events, add
Exam Board Coverage
Basic Probability appears on all major GCSE Maths exam boards at both Foundation and Higher tier.
AQA
Edexcel
OCR
Frequently Asked Questions
What are mutually exclusive events?
Two events are mutually exclusive if they cannot both happen at the same time. If A and B are mutually exclusive, P(A or B) = P(A) + P(B).
What are independent events?
Two events are independent if the outcome of one does not affect the other. If independent, P(A and B) = P(A) × P(B).