12.2.64 Number Theory
Condition: Find the odd double -digit number \ (x \), satisfying the following conditions: the sum of the numbers of the number \ (x \) is equal to \ (y \), the sum of the numbers of the number \ (y \) is \ (z \), while \ (x+y+z = 60 \). How many such numbers exist?
A Huge Number of Interesting Olympiad Problems in Number Theory, and Its Various Section.