Skip to content / Đến nội dung
ThichHocToan.com

MathNet 2022-part-02 — 197 problems (EN–VI) Question 165

Math Olympiad Vault · MathNet 2022-part-02 — 197 problems (EN–VI)

Question 165

A 'palindrome' is a positive integer which reads the same from left to right as from right to left, such as $12321$ and $259952$. Someone wrote down a five-digit palindrome $m$ and then removed a digit of $m$ to obtain a four-digit positive integer $n$ (that does not start with $0$). How many possible values of $n$ are there?