Arithmetic Mean
Source:
June 13, 2009
Problem Statement
The arithmetic mean between \frac {x \plus{} a}{x} and \frac {x \minus{} a}{x}, when x \not \equal{} 0, is:
(A)\ {2}\text{, if }{a \not \equal{} 0}\qquad (B)\ 1\qquad (C)\ {1}\text{, only if }{a \equal{} 0}\qquad (D)\ \frac {a}{x}\qquad (E)\ x