Sequences & Series

Addition Rule and Mutually Exclusive Events

How to find the probability that at least one of two things happens.

Conditional Probability and Independence

How knowing one thing happened changes the odds of another.

Probability Vocabulary and Sample Spaces

Before you can calculate a probability, you need a precise language to describe what can happen.

Theoretical vs Experimental Probability

What probability predicts and what actually happens are two different things — and the gap between them tells you something real.