MathDB
NT 1+ number + 1 = number +14789 Puerto Rico TST 2007.5

Source:

September 15, 2021
number theoryDigits

Problem Statement

Juan wrote a natural number and Maria added a digit 1 1 to the left and a digit 1 1 to the right. Maria's number exceeds to the number of Juan in 1478914789. Find the number of Juan.