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Two standard dice are rolled. What is the probability that the sum of the two numbers is at least 8?

medium 2 marks Class 12 · Mathematics · Probability
Answer
23/36

The correct answer is 23/36 — Probability = favourable/total = 23/36.

Step-by-step solution

  1. Total possible outcomes when rolling two dice = 6 × 6 = 36.
  2. Count favourable outcomes for sums 8,9,10,11,12.
  3. For sum 8: 5 combinations; 9: 6; 10: 5; 11: 4; 12: 3.
  4. Total favourable = 5+6+5+4+3 = 23.
  5. Probability = favourable/total = 23/36.
Common mistake: Missing a combination when counting favourable outcomes.

Concept tested: Discrete random variables – dice sum probability.

Published · How this solution was prepared and checked

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