If the average (arithmetic mean) of three consecutive integers is 21, then the product of the greatest and least integer is  Choose the correct answer
A) 443 B) 442 C) 440 D) 444 E) 441
n = smallest number   n+2 = largest number   (n + n + 2)/2 = 21   =&gt; (2n+2)/2 = 21   =&gt; n + 1 = 21   =&gt; n = 20   So Product of n and n+2 = (20)(22)   = 440   Answer - 440
<result>C</result>
If the average (arithmetic mean) of three consecutive integers is 21, then the product of the greatest and least integer is