Fundamental concepts about relationships between events and methods for calculating their probabilities in various scenarios.
National 5/Higher Applications of Mathematics - Tree diagrams for Two Events.
A Level Maths AQA Notes - Statistics - Probability
A Level AQA Maths - Statistics - Probability (A2 content)
National 5/Higher Applications of Mathematics - Mutually Exclusive Events: Probability.
Notes on the full topic of probability
This is part of gcse maths- both higher and foundation
gcse maths probability notes and set notation explanations