From the set of digits [1,2,3,4,5,6,7,8,9], if two distinct digits are randomly selected, what is the probability that their total will be greater than 15?

Correct answer marked below

\frac{1}{8}

\frac{1}{9}

\frac{1}{18}

Correct

\frac{7}{36}

\frac{5}{36}

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Explanation

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Official Explanation

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To find the total number of ways to choose 2 digits from the set, we calculate 9C2 = 9x8/2 = 36. The pairs that…

Comments

DebraAug 4, 2024

This is exactly what I needed to practice

AshJan 21, 2025

Thank you very much!

What this question tests

Your ability to compute probabilities of single and compound events, including 'at least one' questions.

Forgetting to use the complement for 'at least one', or treating dependent events as independent.