How many whole-number paldinromes exist between 10 and 1000?

Question

A palindrome is a number that is written the same forward as backward. What is the most efficient way of finding all those numbers?

Answer 1

11, 22, ...99, 111, 222, ...999

that's 18

also

101, 202, ..., 909,

121, 323, ..., 939

...

919, 929, ..., 989

that's another 72

total: 18+72= 90

out of 991 numbers