2^a7^b=2^c7^d (mod 15) iff 3^a5^b =3^c5^d (mod 16)
Source: 1999 Estonia National Olympiad Final Round grade 12 p1
March 11, 2020
number theoryremainderpower of 2power of 3
Problem Statement
Let and be non-negative integers. Prove that the numbers and give the same remainder when divided by iff the numbers and give the same remainder when divided by .