Basic rules

Math

Definition

Fundamental probability rules including the addition rule (for 'or' events), the multiplication rule (for 'and' events), and the complement rule. These rules form the foundation for all probability calculations.

Examples

  • P(A or B) = P(A) + P(B) − P(A and B) for any two events
  • P(not A) = 1 − P(A): the probability of not rolling a 6 is 1 − 1/6 = 5/6
Key Fact

P(A or B) = P(A) + P(B) − P(A∩B); P(A') = 1 − P(A)

Related Terms

Basic probability Probability rules Binomial probability Conditional statements

Study This Concept

Practice basic rules with free review games in these units:

AP Calculus AB Unit 2: Differentiation: Definition