The word "or" in probability implies that we use the ______ Rule.

Verified step by step guidance

1. Understand that in probability, the word "or" typically refers to the event that either one event or another event (or both) occurs.
2. Recall that the rule used to find the probability of "A or B" is called the Addition Rule.
3. The Addition Rule states that the probability of the union of two events A and B is given by the formula: \(P(A \text{ or } B) = P(A \cup B) = P(A) + P(B) - P(A \cap B)\).
4. This formula accounts for the fact that if events A and B are not mutually exclusive, the overlap (intersection) is subtracted to avoid double counting.
5. Therefore, whenever you see "or" in a probability problem, you apply the Addition Rule to calculate the combined probability.

Key Concepts

Addition Rule in Probability

The Addition Rule is used to find the probability that either one event or another event occurs. It states that P(A or B) = P(A) + P(B) - P(A and B), accounting for any overlap between events to avoid double counting.

Mutually Exclusive Events

Mutually exclusive events cannot happen at the same time, meaning their intersection is zero. For such events, the Addition Rule simplifies to P(A or B) = P(A) + P(B) because there is no overlap.

Probability of Events

Probability measures the likelihood of an event occurring, ranging from 0 (impossible) to 1 (certain). Understanding how to calculate and interpret probabilities is essential for applying rules like the Addition Rule correctly.