USAMO 1983 Problem 5 - Open interval of length 1/n
Source: USAMO 1983 Problem 5
August 16, 2011
AMCUSA(J)MOUSAMOnumber theory unsolvednumber theory
Problem Statement
Consider an open interval of length on the real number line, where is a positive integer. Prove that the number of irreducible fractions , with , contained in the given interval is at most .