MathDB
Kosovo National MO Grade 11.

Source:

July 16, 2017
number theory

Problem Statement

Find all ordered pairs (a,b)(a,b), of natural numbers, where 1<a,b1001<a,b\leq 100, such that 1loga10+1logb10\frac{1}{\log_{a}{10}}+\frac{1}{\log_{b}{10}} is a natural number.