2012-2013 Winter OMO #12
Source:
January 16, 2013
Online Math Openanalytic geometry
Problem Statement
There are 25 ants on a number line; five at each of the coordinates , , , , and . Each minute, one ant moves from its current position to a position one unit away. What is the minimum number of minutes that must pass before it is possible for no two ants to be on the same coordinate?Ray Li