How many pairs of 4 digit palindromes add up to a five digit palindrome?
Discussed in attached images.
This problem is from the PMONK Pertandingan Matematik Olympiad Peringkat Negeri Kedah 2018 – Grade 5 and 6 – No. 24 (last question and probably the toughest problem on this paper).
It is also closely related to Problem 13 on the IMC 2013 (Grade 6).