What are events called when two or more events cannot occur at the same time?

The correct answer is that events are called mutually exclusive when two or more events cannot occur at the same time. This concept is fundamental in probability theory and statistics. Mutually exclusive events imply that the occurrence of one event precludes the occurrence of another. For example, if you flip a coin, the result can either be heads or tails, but not both simultaneously.

Understanding mutually exclusive events is crucial when calculating probabilities, as the probability of either event occurring can be found by adding their individual probabilities. This contrasts with independent events, where the occurrence of one event does not affect the occurrence of another, and dependent events, where the outcome of one event depends on another. Random events, while they might occur without discernible patterns, do not carry the specific characteristic of mutual exclusivity.