Bunuel wrote:
The sum of seven consecutive integers is equal to 7. What is the average of the greatest and least terms in the series?
(A) 7
(B) 4
(C) 2
(D) 1
(E) -2
Since 7 consecutive integers sum to 7, we can let x = the first integer and create the following equation:
x + x + 1 + x + 2 + x + 3 + x + 4 + x + 5 + x + 6 = 7
7x + 21 = 7
7x = -14
x = -2
Thus, the first integer is -2 and the seventh integer is 4. The average of those integers is (-2 + 4)/2 = 1.
Answer: D