maths

anne tew:

Find the sum of the integers from 17 to 82 inclusive.

82+17=99

1 row: 17, 18, 19 ...
2 row: 82, 81, 80 ...
column-sum is always: 99

"17 to 82 inclusive" => 66 elements

66 * 99 / 2 = 3267