Final answer:
Two events A and B are mutually exclusive if they cannot occur at the same time. Mathematically, P(A AND B) = 0. The probability of either event occurring is given by P(A OR B) = P(A) + P(B).
Step-by-step explanation:
Two events A and B are considered mutually exclusive if they cannot occur at the same time. In other words, if A happens, then B cannot happen, and vice versa. Mathematically, this is represented as P(A AND B) = 0.
For example, let's consider the events of drawing a blue card and drawing a red or green card from a deck of cards. These events are mutually exclusive because a card cannot be both blue and (red or green) at the same time.
Therefore, if two events A and B are mutually exclusive, the probability of either event occurring is given by P(A OR B) = P(A) + P(B).