What is the sum of all consecutive multiples of 8 between 400 and 600, inclusive? Options:
A) 8000  B) 10,400  C) 12,500  D) 13,000  E) 15,000
400 is 8*50 and 600 is 8*75...   Average of 400 and 600= 500, extreme multiples of 8..   # of multiples of 8 =75-50+1=26..   Sum =#*avg= 26*500= 
<gadget id="calculator">26*500</gadget>
<output>13_000</output>
13000   ANSWER:13,000
<result>D</result>
What is the sum of all consecutive multiples of 8 between 400 and 600, inclusive?