What is the average (arithmetic mean) of all the multiples of ten from 10 to 210 inclusive? Pick: A) 90 B) 95 C) 100 D) 120 E) 110
10 and 190 inclusive would mean there are 21 terms.   No need to add up all the terms and further divide by 21 since the terms are evenly spaced in ascending order from 10, 20, 30........210   The middle term is the average which is the tenth term = 120   120 is the answer.
<result>D</result>
What is the average (arithmetic mean) of all the multiples of ten from 10 to 210 inclusive?