MathDB
1988 AJHSME #21

Source:

June 21, 2011

Problem Statement

A fifth number,nn , is added to the set {3,6,9,10} \{ 3,6,9,10\} to make the mean of the set of five numbers equal to its median. The number of possible values of nn is
(A) 1(B) 2(C) 3(D) 4(E) more than 4 \text{(A)}\ 1\qquad\text{(B)}\ 2\qquad\text{(C)}\ 3\qquad\text{(D)}\ 4\qquad\text{(E)}\ \text{more than }4