The average (arithmetic mean) of the even integers from 0 to 40 inclusive is how much greater than the average (arithmetic mean) of the even integers from 0 to 20 inclusive?
Choose the correct choice from the following answers:
A) 5	B) 8	C) 10	D) 15	E) 20
The sum of even numbers from 0 to N is 2 + 4 +...+ N   = 2(1 + 2 + ...+ N/2)   = 2(N/2)(N/2+1)/2 = (N/2)(N/2+1)   The average is (N/2)(N/2+1)/(N/2+1) = N/2   The average of the even numbers from 0 to 40 is  40/2= 
<gadget id="calculator"> 40/2</gadget>
<output>20</output>
20   The average of the even numbers from 0 to 20 is  20/2= 
<gadget id="calculator"> 20/2</gadget>
<output>10</output>
10   The answer is 10.
<result>C</result>
The average (arithmetic mean) of the even integers from 0 to 40 inclusive is how much greater than the average (arithmetic mean) of the even integers from 0 to 20 inclusive?