the average ( arithmetic mean ) of the even integers from 24 to 48 inclusive is how much greater than the average ( arithmetic mean ) of the even integers from 12 to 24 inclusive ?
"so , according to a mean of a set of even numbers from 24 to 48 = ( 24 + 48 ) / 2 = 36 and mean of a set of even numbers from 12 to 24 = ( 12 + 24 ) / 2 = 18 difference = 36 - 18 = 18 answer : c ."
subtract(divide(add(24, 12), const_2), divide(add(48, 24), const_2))