| compound event | An event with more than one outcome. |
| equally likely | Having the same likelihood of occurring, such that in a large number of trials, two equally likely outcomes would happen roughly the same number of times. |
| event | A collection of possible outcomes, often describable using a common characteristic, such as rolling an even number with a die or picking a card from a specific suit. |
| event space | The set of possible outcomes in an event: for example, the event “rolling an even number” on a die has the event space of 2, 4, and 6. |
| Fundamental Counting Principle | If one event has p possible outcomes, and another event has m possible outcomes, then there are a total of p • m possible outcomes for the two events. |
| outcome | A result of a trial. |
| probability | A measure of how likely it is that something will occur. |
| sample space | The set of all possible outcomes. |
| simple event | An event with only one outcome. |
| tree diagram | A diagram that shows the choices or random outcomes from multiple trials, using branches for each new outcomes. |
| trial | A random action or series of actions. |