The Sum of first N consecutive odd integers is N^2. What is the sum of all odd integers between 11 and 41 inclusive.  Options:
A) 351 B) 364 C) 416 D) 424 E) 450
We're dealing with a sequence of CONSECUTIVE ODD INTEGERS: 11 to 41, inclusive. We're asked for the SUM of this group.   1) Start with the sum of the smallest and the biggest:   11 + 41= 
<gadget id="calculator">  11 + 41</gadget>
<output>52</output>
52   2) Now look at the 'next smallest' and the 'next biggest': 13 + 39= 
<gadget id="calculator">13 + 39</gadget>
<output>52</output>
52   Now we have proof that there is no middle term. We have 8 bunches of 52.   8(52)= 416   416
<result>C</result>
The Sum of first N consecutive odd integers is N^2. What is the sum of all odd integers between 11 and 41 inclusive.