Answer:
The answer is 39.
Step-by-step explanation:
I will divide the range into 5 division to count palindromes more easy.
<u>From 10 to 100:</u>
11
There are only 1 number exist that at least the digit 1 appears once.
<u>From 100 to 1000:</u>
<u>Section 1:</u>
_1_ (e.g. 212)
There are be 9 numbers exist that at least the digit 1 appears once from above number structure.
<u>Section 2:</u>
1_1 (e.g. 121)
There are be 10 numbers exist that at least the digit 1 appears once from above number structure.
<u>From 1000 to 10000:</u>
<u>Section 1:</u>
1__1 (e.g. 1221)
There are be 10 numbers exist that at least the digit 1 appears once from above number structure.
<u>Section 2:</u>
_11_ (e.g. 2112)
There are be 9 numbers exist that at least the digit 1 appears once from above number structure.