Question

Numbers that are palindromes read the same forward and backward. For​ example, 30203 is a​ five-digit palindrom. If a single number is chosen randomly from the set of all​ two-digit numbers, find the probability that it will be palindromic.
The probability that a randomly chosen​ two-digit number is palindromic is ____.

Answer 1

For a two-digit number to be palindromic, the two digits must be the same.

Number of two-digit numbers with the two digits equal is 9. (i.e. 11, 22, 33, . . . )

Total number of two-digit numbers is 90.

Therefore, the probability that a randomly chosen​ two-digit number is palindromic is 1 / 10 or 0.1.