Question
Download Solution PDFIf two fair dice are tossed, then what is the probability that the sum of the numbers on the faces of the dice is strictly greater than 7?
Answer (Detailed Solution Below)
Detailed Solution
Download Solution PDFCalculation:
Given,
Two fair six-sided dice are rolled.
Each die has faces numbered 1 through 6.
Total number of outcomes:
Since each die has 6 faces, the sample space size is
\(N = 6 \times 6 = 36\).
Favourable outcomes (sum > 7):
We list all ordered pairs ((i, j)) with (i + j > 7):
Sum = 8: (2,6), (3,5), (4,4), (5,3), (6,2) → 5 outcomes
Sum = 9: (3,6), (4,5), (5,4), (6,3) → 4 outcomes
Sum = 10: (4,6), (5,5), (6,4) → 3 outcomes
Sum = 11: (5,6), (6,5) → 2 outcomes
Sum = 12: (6,6) → 1 outcome
Total favourable outcomes = (5 + 4 + 3 + 2 + 1 = 15).
Probability calculation:
The probability that the sum is strictly greater than 7 is
\(P(\text{sum} > 7) = \frac{\text{favourable outcomes}}{\text{total outcomes}} = \frac{15}{36} = \frac{5}{12}\).
Hence, the correct answer is Option 2.
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