1. **State the problem:** We are given a Venn diagram with events A and B in a sample space S. We need to find the probability of the union of A and B, denoted as $P(A \cup B)$.
2. **Recall the formula:** The probability of the union of two events is given by:
$$P(A \cup B) = P(A) + P(B) - P(A \cap B)$$
This formula accounts for the overlap so we don't double-count the intersection.
3. **Identify values from the diagram:**
- $P(A \text{ only}) = 45$
- $P(B \text{ only}) = 15$
- $P(A \cap B) = 15$
- $P(\text{outside both}) = 25$
4. **Calculate total sample space size:**
$$|S| = 45 + 15 + 15 + 25 = 100$$
5. **Calculate probabilities:**
- $P(A) = \frac{45 + 15}{100} = \frac{60}{100} = 0.6$
- $P(B) = \frac{15 + 15}{100} = \frac{30}{100} = 0.3$
- $P(A \cap B) = \frac{15}{100} = 0.15$
6. **Apply the formula:**
$$P(A \cup B) = 0.6 + 0.3 - 0.15 = 0.75$$
7. **Final answer:**
$$\boxed{0.75}$$
Probability Union D88180
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