The average (arithmetic mean) of the even integers from 20 to 60 inclusive is how much greater than the average (arithmetic mean) of the even integers from 10 to 140 inclusive? Choose the correct choice from the following options.
A) 40 B) 15 C) 35 D) 20 E) 25

Rationale: so , according to a mean of a set of even numbers from 20 to 60 = ( 20 + 60 ) / 2 = 40 and mean of a set of even numbers from 10 to 140 = ( 10 + 140 ) / 2 = 75 difference = 75 - 40 = 35 answer : c .
Answer: C