Introduction To Probability

Probability is the mathematics of chance. Every time you toss a coin, roll a die, draw a card or check tomorrow's weather forecast, you are dealing with uncertainty, and probability gives you a precise way to measure how likely something is. Instead of vague words like likely or unlikely, it puts a number between 0 and 1 on every event.

In this lesson you will meet the probability scale, learn the simple formula that turns counting into probability, and discover the neat shortcut that the chance of something not happening is just one minus the chance that it does. These ideas are the foundation of every probability question you will ever meet, so getting them solid now pays off all the way through the course.