2003 AIME I Problem 14

The decimal representation of m/n, where m and n are relatively prime positive integers and m < n, contains the digits 2, 5, and 1 consecutively, and in that order. Find the smallest value of n for which this is possible.

Leading zeroes must be inputted, so if your answer is 34, then input 034

Full credit goes to MAA for authoring these problems. These problems were taken on the AOPS website.