Question
A palindrome is a number that reads the same forwards as it does backwards. For example, 98789 is a 5-digit palindrome, and 7337 is a 4-digit palindrome. How many 3-digit palindromes are there?
Answers
Reiny
Assuming that we can't start with 0 , or else it would be a 2 - digit number,
there are 9 choices for the 1st, then only 1 at the end
the middle can be any of the 10
number of such numbers
= 9 x 10 x 1 = 90
there are 9 choices for the 1st, then only 1 at the end
the middle can be any of the 10
number of such numbers
= 9 x 10 x 1 = 90