Odd-only subsets with two of 1, 2, 3
Question
Consider subsets of in which every element is odd and which contain exactly two of the numbers . How many such subsets are there?
Short answer
. The only odd pair from is , so both must be included. The other odd numbers may each be in or out freely, giving subsets.
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Open the worked solutionLessons behind this question
- Counting and Combinatorics
- Sample Spaces, Events, and the Probability Axioms
- Conditional Probability, Total Probability, and Bayes' Rule
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