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Suppose you roll a pair of six-sided dice.

(a) What is the probability that the sum of the numbers on your dice is exactly 4?




(b) What is the probability that the sum of the numbers on your dice is at most 7?



(c) What is the probability that the sum of the numbers on your dice is at least 10?

User Akhaku
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Answer:

Explanation:

To calculate the probabilities for the various outcomes when rolling a pair of six-sided dice, you can use a probability distribution table or a visual representation of all possible outcomes. There are 36 equally likely outcomes when rolling two dice (6 faces on the first die times 6 faces on the second die).

(a) Probability that the sum of the numbers on your dice is exactly 4:

You can achieve a sum of 4 in the following ways:

1. (1, 3)

2. (2, 2)

3. (3, 1)

There are 3 favorable outcomes.

Probability = (Number of favorable outcomes) / (Total number of possible outcomes) = 3 / 36 = 1 / 12

(b) Probability that the sum of the numbers on your dice is at most 7:

To find the probability of getting a sum at most 7, you need to calculate the probability of getting a sum of 2, 3, 4, 5, 6, or 7. You've already calculated the probability of a sum of 4 in part (a). Now, for the other sums:

Sum of 2:

There's one way to get a sum of 2: (1, 1).

Sum of 3:

There are two ways to get a sum of 3: (1, 2) and (2, 1).

Sum of 5:

There are four ways to get a sum of 5: (1, 4), (2, 3), (3, 2), and (4, 1).

Sum of 6:

There are five ways to get a sum of 6: (1, 5), (2, 4), (3, 3), (4, 2), and (5, 1).

Sum of 7:

There are six ways to get a sum of 7: (1, 6), (2, 5), (3, 4), (4, 3), (5, 2), and (6, 1).

Total favorable outcomes for sums at most 7: 1 (sum of 2) + 2 (sum of 3) + 3 (sum of 4) + 4 (sum of 5) + 5 (sum of 6) + 6 (sum of 7) = 21 favorable outcomes.

Probability = (Number of favorable outcomes) / (Total number of possible outcomes) = 21 / 36 = 7 / 12

(c) Probability that the sum of the numbers on your dice is at least 10:

To find the probability of getting a sum at least 10, you need to calculate the probability of getting a sum of 10 or 11 or 12.

Sum of 10:

There are three ways to get a sum of 10: (4, 6), (5, 5), and (6, 4).

Sum of 11:

There are two ways to get a sum of 11: (5, 6) and (6, 5).

Sum of 12:

There's one way to get a sum of 12: (6, 6).

Total favorable outcomes for sums at least 10: 3 (sum of 10) + 2 (sum of 11) + 1 (sum of 12) = 6 favorable outcomes.

Probability = (Number of favorable outcomes) / (Total number of possible outcomes) = 6 / 36 = 1 / 6

User Rich Oliver
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