Multiple choice

If two dice are rolled, then find the probability that the sum of the two numbers obtained is a prime number.

  1. 7 12

  2. 5 12

  3. 1 4

  4. 3 4

  5. None of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Total outcomes = 36. Prime sums are 2, 3, 5, 7, 11. Outcomes: (1,1), (1,2), (2,1), (1,4), (4,1), (2,3), (3,2), (1,6), (6,1), (2,5), (5,2), (3,4), (4,3), (5,6), (6,5). Total = 15. Probability = 15/36 = 5/12.

AI explanation

When two dice are rolled, the total number of possible outcomes is 6 times 6, or 36. The prime sums possible are 2, 3, 5, 7, and 11, which account for 15 total combinations. Using the classical probability formula, the probability is 15/36, which simplifies to 5/12.

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