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Unformatted text preview: noor dont know. The article says that a person is credulous if he or she answers at least 6 of the questions with a yes. How many ways are there to answer the questions so that you receive the label credulous? 4. Let S be an n-set. It was shown in the text (and in class) that the number of subsets that can be formed from S is 2 n . Generalize this: State and prove a formula for the number of multisets that can be formed from S where each element is repeated at most k times . When k = 1, your formula should become 2 n . 5. Let S ( n, k ) be the Stirling numbers of the second kind; that is, S ( n, k ) is the number of ways to partition an n-set into k unordered blocks. Prove that S ( n, k ) = n X j =1 n-1 j-1 S ( n-j, k-1) for n > 0 and k > 0. END OF EXAM...
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- Winter '08