Mathematics · Average

The average of four consecutive odd numbers is [x + 8]. The average of four consecutive even numbers is [y + 4]. The third number in the odd series is equal to the average of the even series, and the second number of the even series is equal to the average of the odd series. The lowest number of the odd series is one less than the lowest number of the even series. If the sum of x and y is 25, find the absolute difference between x and y.