Lesson eLearning

A die is rolled twice. Find the probability that the sum of the two rolls is greater than 8.

medium 2 marks Class 11 · Mathematics · Probability
Answer
5/18

The correct answer is 5/18 — Probability = 10/36 =5/18.

Step-by-step solution

  1. Total possible outcomes of two rolls = 6*6 =36.
  2. List sums greater than 8: 9,10,11,12.
  3. Count ordered pairs for each sum: Sum 9: (3,6),(4,5),(5,4),(6,3) →4 Sum 10: (4,6),(5,5),(6,4) →3 Sum 11: (5,6),(6,5) →2 Sum 12: (6,6) →1 Total favourable = 4+3+2+1 =10.
  4. Probability = 10/36 =5/18.
Common mistake: Counting unordered pairs instead of ordered, or forgetting (6,6)

Concept tested: Compound probability for sum of dice

Published · How this solution was prepared and checked

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