Difficulty: Easy
Correct Answer: 2/9
Explanation:
Introduction / Context:
We aggregate favorable outcomes for three different target sums and divide by 36.
Given Data / Assumptions:
Concept / Approach:
Count outcomes for each sum and add them.
Step-by-Step Solution:
Sum 3: (1,2), (2,1) → 2 outcomes.Sum 5: (1,4), (2,3), (3,2), (4,1) → 4 outcomes.Sum 11: (5,6), (6,5) → 2 outcomes.Total favorable = 2 + 4 + 2 = 8.Probability = 8 / 36 = 2 / 9.
Verification / Alternative check:
Check that counts align with standard sum-distribution table for two dice.
Why Other Options Are Wrong:
5/36 applies to sum 8; 1/9 is 4/36 (too small); 19/36 is much too large; 7/36 undercounts by one outcome.
Common Pitfalls:
Missing symmetric pairs (e.g., both (2,3) and (3,2)).
Final Answer:
2/9
Discussion & Comments