Average of the Terms in a Sequence
Source:
January 18, 2009
Problem Statement
Consider the sequence 1, \minus{} 2,3, \minus{} 4,5, \minus{} 6,\ldots, whose th term is ( \minus{} 1)^{n \plus{} 1}\cdot n. What is the average of the first terms of the sequence? (A)\minus{}\!1\qquad (B)\minus{}\!0.5\qquad (C)\ 0\qquad (D)\ 0.5\qquad (E)\ 1