CombinatoricsDifficulty 5.0AIME, harderFind the answerUnited Kingdom
Deindra wants to arrange the five numbers 1, 2, 3, 4, and 5 into a row such that the last number is odd, and the sum of any three adjacent numbers is divisible by the first number of the three. How many such arrangements could she make?
(A) 1 (B) 2 (C) 3 (D) 4 (E) 5
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