HockeyStickFormula
AIME
Difficult
2015
Consider all $1000$-element subsets of the set $\{1, 2, 3, ... , 2015\}$. From each such subset choose the least element. Find the arithmetic mean of all of these least elements.
The solution for this problem is available for
$0.99.
You can also purchase a pass for all available solutions for
$99.