If you think about the digits, you can rewrite them as ABBA, with A being one digit and B being another: A can be 1-9 and B can be 0-9. Since A has to be 1, B can be 0-9, leaving 10 palindromic numbers.
2100
1111 is the only one.
1100
1000, 1020, 1040, 1060, 1080, and 1100
1001, 1012, 1023, 1034, 1045, 1056, 1067, 1078, 1089, 1100
2100
1111 is the only one.
1100
1000, 1020, 1040, 1060, 1080, and 1100
Since all the numbers in that range start with "11", there is really only one option!
The answer between 1 and 1000 is 840, but what about 1 and 1100?
1,001 1,012 1,023 1,034 1,045 1,056 1,067 1,078 1,089
The answer is 1100. Simply add the numbers together arithmetically as you would for the problem two plus two. To check your work, a calculator is the best option.
Two: 1020 and 1080.
1001, 1012, 1023, 1034, 1045, 1056, 1067, 1078, 1089, 1100
1100
1100