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algebra senior
Problem
What is the greatest number of consecutive integers whose sum is
(A)
(B)
(C)
(D)
Solution
We might at first think that the answer would be , because when . But note that the problem says that they can be integers, not necessarily positive. Observe also that every term in the sequence cancels out except . Thus, the answer is, intuitively, integers. Though impractical, a proof of maximality can proceed as follows: Let the desired sequence of consecutive integers be , where there are terms, and we want to maximize . Then the sum of the terms in this sequence is . Rearranging and factoring, this reduces to . Since must divide , and we know that is an attainable value of the sum, must be the maximum.
Final answer
D