How Do I Calculate Probability?

Florian Murauer / EyeEm/Eye/Em/Getty Images

The theoretical definition of probability states that if the outcomes of an event are mutually exclusive and equally likely to happen, then the probability of the outcome "A" is: P(A) = Number of outcomes that favors A / Total number of outcomes. For example, there are two possible outcomes when a coin is tossed in the air, and the probability of the coin landing on a head or a tail is equal to 0.5.