If the average (arithmetic mean) of five consecutive integers is k + 2, then the product of the greatest and least integer is
Pick one: A) k^2 - 9 B) k^2 - 2k + 1 C) k^2 + 4k D) k^2 + 6k + 9 E) k^2 + 4k - 12
n = smallest number   n+4 = largest number   (n + n + 4)/2 = k+2   =&gt; (2n+4)/2 = k+ 2   =&gt; n + 2 = k + 2   =&gt; n = k   So Product of n and n+4 = (k)(k+4)   = k^2 + k   = k^2 + 4k   Answer - k^2 + 4k
<result>C</result>
If the average (arithmetic mean) of five consecutive integers is k + 2, then the product of the greatest and least integer is