AMC 12B 2025 (Problem 23)
Let be the set of all integers such that for all pairs of nonnegative integers with , the remainder when is divided by is less than the remainder when is divided by . What is the sum of the elements of ?
Let be the remainder of when divided by .
If ,
If ,
If ,
For ,
Since there are distinct remainders between and ,
Since there are distinct remainders between and ,
(E)