odd sum of a 3-digit number with it's ''inverted'' 201& May Olympiad L1 p1
Source:
August 25, 2021
number theoryDigitsodd
Problem Statement
To each three-digit number, Matías added the number obtained by inverting its digits. For example, he added to the number . Calculate in how many cases the result of the sum of Matías is a number with all its digits odd.