Summary - Maths

This probability reference sheet covers key set and probability concepts, starting with six Venn diagram rules: union (A or B or both), intersection (both A and B), complement (not in A), mutually exclusive (no overlap), A only (A but not B), and B only (B but not A), plus a tip for correct shading. It also includes core probability formulas—such as the basic probability definition, the complement rule, and rules for mutually exclusive, independent, and conditional events—alongside the addition law for unions. Additionally, it explains combinations (for selections where order does not matter) using the combination formula and key identities, and notes that both Venn diagrams and Karnaugh maps are useful tools for visualising and calculating probabilities.