MathDB
Product of two integers is congruent 1 mod the third

Source: 1990 Bundeswettbewerb Mathematik, Round 2 - #1

September 11, 2015
remaindernumber theory

Problem Statement

Find all triples (a,b,c)(a,b,c) of positive integers such that the product of any two of them when divided by the third leaves the remainder 11.