To find the probability of rolling two number cubes (dice) and getting a sum of 6 or 11, we need to first calculate the individual probabilities and then combine them.
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Calculating the probability of getting a sum of 6: The possible combinations that give a sum of 6 are:
- (1, 5)
- (2, 4)
- (3, 3)
- (4, 2)
- (5, 1)
There are 5 combinations that result in a sum of 6.
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Calculating the probability of getting a sum of 11: The possible combinations that give a sum of 11 are:
- (5, 6)
- (6, 5)
There are 2 combinations that result in a sum of 11.
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Total combinations when rolling two dice: There are 36 possible outcomes (6 sides on the first die * 6 sides on the second die = 36).
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Finding the individual probabilities:
- Probability of getting a sum of 6: \( \frac{5}{36} \)
- Probability of getting a sum of 11: \( \frac{2}{36} \)
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Combining the probabilities for a sum of 6 or 11: To find the overall probability of obtaining a sum of 6 or 11, we add the two probabilities together:
\[ \text{Total Probability} = \frac{5}{36} + \frac{2}{36} = \frac{7}{36} \]
Now, let's look at the options provided:
- \( 636 \cdot 236 \) (incorrect)
- \( \frac{6}{36} \times \frac{2}{36} \) (incorrect)
- \( 536 + 236 \) (incorrect)
- \( \frac{5}{36} + \frac{2}{36} \) (correct)
The correct calculation is \( \frac{5}{36} + \frac{2}{36} \).
Therefore, the answer is:
Start Fraction 5 over 36 End Fraction plus Start Fraction 2 over 36 End Fraction