For any positive integer n, the sum of the first n positive integers equals [n(n+1)]/2.
What is the sum of all the even integers between 99 and 191?
Select
A) 4450 B) 5560 C) 6670 D) 7780 E) 8890
100 + 102 +...+ 190 = 46*100 + (2+4...+90) = 46*100 + 2(1+2+...+45) =   46*100 + 2(45)(46)/2 = 145*46= 
<gadget id="calculator">145*46</gadget>
<output>6_670</output>
6670   The answer is 6670.
<result>C</result>
For any positive integer n, the sum of the first n positive integers equals [n(n+1)]/2.
What is the sum of all the even integers between 99 and 191?