The sum of the first n positive perfect squares, where n is a positive integer, is given by the formula n3/3 + cn2 + n/6, where c is a constant. What is the sum of the first 15 positive perfect squares?  Choices.
A) 1,010	B) 1,164	C) 1,240	D) 1,316	E) 1,476
For n=1,   1=1/3 + c + 1/6   1=1/2 + c   =&gt; c = 1/2   15*15*15/3 + 1/2*15*15 + 15/6= 
<gadget id="calculator">15*15*15/3 + 1/2*15*15 + 15/6</gadget>
<output>1_240</output>
1240   ANSWER:1,240
<result>C</result>
The sum of the first n positive perfect squares, where n is a positive integer, is given by the formula n3/3 + cn2 + n/6, where c is a constant. What is the sum of the first 15 positive perfect squares?