Problem #PRU-100549

Problems Combinatorics

Problem

A palindromic number is a number that reads the same backward and forward. (For example, \(13531\) is palindromic.)

a) How many \(5\)-digit numbers are palindromic?

b) How many \(5\)-digit numbers are palindromic and consist of distinct digits?

c) How many \(5\)-digit numbers consist of \(3\) distinct digits and end with 2?

d) How many \(5\)-digit numbers are odd and consist of \(3\) distinct digits?