MathDB
Sum of digits

Source: PRMO 2019 Leg 2 P7

August 25, 2019
algebraPRMOnumber theorydecimal representation

Problem Statement

Let s(n)s(n) denote the sum of digits of a positive integer nn in base 1010. If s(m)=20s(m)=20 and s(33m)=120s(33m)=120, what is the value of s(3m)s(3m)?