Dhaka Junior 2011/5
Posted: Wed Feb 02, 2011 8:23 am
5. A palindrome, such as $83438$, is a number that remains the same when its digits are reversed. How many four digit numbers are not palindromes?
The Official Online Forum of BdMO
4 digit number starts from 1000 soMehfuj Zahir wrote:Four digit palindrome number should be like ABBA.If u reverse it u will get also ABBA.At first we will count how many numbers are palindrome.It is enough to count AB.SO we will get the result 9o.Then the ans 10000-90=9910
surjo wrote:I did not get it. 9*9=81 should be palindromic numbers