1. The problem is to define the term "mutually exclusive" in a clear and precise way. 2. In probability and set theory, two events are called mutually exclusive if they cannot happen at the same time. 3. This means that the occurrence of one event excludes the possibility of the other event occurring. 4. Mathematically, if $A$ and $B$ are two events, they are mutually exclusive if their intersection is empty: $$ A \cap B = \emptyset $$ 5. In probability terms, this means: $$ P(A \cap B) = 0 $$ 6. So, mutually exclusive events have no outcomes in common. 7. For example, when flipping a coin, the events "heads" and "tails" are mutually exclusive because the coin cannot land on both sides at once. Final answer: Mutually exclusive events are events that cannot occur simultaneously, i.e., their intersection is empty and $P(A \cap B) = 0$.