Bangladesh Mathematical Olympiad 2020
Source: BdMO 2020 Final Primary Category Problem 10
August 30, 2020
number theoryNumber system
Problem Statement
Sokal da tries to find out the largest positive integer n such that if n transforms to base-7, then it looks like twice of base-10. is such a number because = and 312 = 2156. Find out Sokal da's number.