How do you calculate an average-of-all-even-numbers-between-1-and-100?

Answer 1

The average of the smallest and the largest even numbers (2 and 98) is 50

The average of the next smallest and the next largest (4 and 96) is 50

The average of the next smallest and the next largest (6 and 94) is 50

and so on.

So, the overall average is 50.