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Probability is a branch of mathematics that describes how likely an event is to occur. It is a number between 0 and 1, where 0 means the event will not happen and 1 means the event will happen.
Probabilities are usually expressed as fractions, decimals, or percentages. For example, a probability of 0.45 (45%) means there are 45 chances out of 100 of an event occurring. Probability tells us how often some event will happen after many repeated trials. You've experienced probability when you've flipped a coin, rolled some dice, or looked at a weather forecast.
There are three basic rules associated with probability: the addition, multiplication, and complement rules.
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