1. **Problem Statement:** Two fair dice are rolled simultaneously. We need to find:
- The probability that the sum of the numbers is an even number greater than 7.
- The probability that at least one die shows a 5.
- The probability that either event 1 or event 2 occurs.
2. **Total possible outcomes:** Each die has 6 faces, so total outcomes = $6 \times 6 = 36$.
3. **Event 1: Sum is an even number greater than 7.**
- Even sums greater than 7 are 8, 10, and 12.
- List outcomes for each sum:
- Sum = 8: (2,6), (3,5), (4,4), (5,3), (6,2)
- Sum = 10: (4,6), (5,5), (6,4)
- Sum = 12: (6,6)
- Total favorable outcomes for event 1 = $5 + 3 + 1 = 9$.
- Probability(event 1) = $\frac{9}{36} = \frac{1}{4}$.
4. **Event 2: At least one die shows a 5.**
- Outcomes where first die is 5: (5,1), (5,2), (5,3), (5,4), (5,5), (5,6) → 6 outcomes
- Outcomes where second die is 5: (1,5), (2,5), (3,5), (4,5), (6,5) → 5 outcomes (excluding (5,5) counted before)
- Total favorable outcomes for event 2 = $6 + 5 = 11$.
- Probability(event 2) = $\frac{11}{36}$.
5. **Event 1 and Event 2 intersection:** Outcomes where sum is even >7 and at least one die is 5.
- From event 1 outcomes, those with a 5:
- Sum=8: (3,5), (5,3)
- Sum=10: (5,5)
- Total intersection outcomes = 3.
- Probability(event 1 and event 2) = $\frac{3}{36} = \frac{1}{12}$.
6. **Probability of either event 1 or event 2 occurring:**
- Use formula: $P(A \cup B) = P(A) + P(B) - P(A \cap B)$
- $= \frac{1}{4} + \frac{11}{36} - \frac{1}{12} = \frac{9}{36} + \frac{11}{36} - \frac{3}{36} = \frac{17}{36}$.
**Final answers:**
- Probability(sum even >7) = $\frac{1}{4}$
- Probability(at least one 5) = $\frac{11}{36}$
- Probability(either event) = $\frac{17}{36}$
Dice Probability 9119Cf
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