digits' problem, last digit 2
Source: VII May Olympiad (Olimpiada de Mayo) 2001 L1 P1
September 22, 2022
number theoryDigits
Problem Statement
Sara wrote on the board an integer with less than thirty digits and ending in . Celia erases the from the end and writes it at the beginning. The number that remains written is equal to twice the number that Sara had written. What number did Sara write?