In a given experiment, the probabilities of all mutually exclusive events sum to one.

Question

Quizplus · Accepted Answer

This statement is true by the definition of mutually exclusive events. Mutually exclusive events cannot occur at the same time, so the probability of any one of them occurring is mutually exclusive from the probability of any other one occurring. Therefore, the sum of all the probabilities of the mutually exclusive events must equal one, since one of the events must occur.

In a Given Experiment, the Probabilities of All Mutually Exclusive