MathDB
Find posible values of gcd

Source: Argentina IMO TST 2007 problem 1

August 27, 2009
number theorygreatest common divisoralgebra unsolvedalgebra

Problem Statement

Let X X, Y Y, Z Z be distinct positive integers having exactly two digits in such a way that: X\equal{}10a \plus{}b Y\equal{}10b \plus{}c Z\equal{}10c \plus{}a (a,b,c a,b,c are digits) Find all posible values of gcd(X,Y,Z) gcd(X,Y,Z)