mutually exclusive. This means that if one event occurs, the other event cannot occur. For example, the events "rolling a 6 on a die" and "rolling a 3 on a die" are mutually exclusive because it is impossible to roll a 6 and a 3 at the same time. Similarly, the events "getting a tail when flipping a coin" and "getting a head when flipping a coin" are also mutually exclusive because it is impossible to get both a tail and a head at the same time when flipping a coin. In probability theory, the probability that two mutually exclusive events will both occur is zero.