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The number 121 is a palindrome, because it reads the same backwards as forward. How many integer palindromes are between 100 and 500?

 Aug 31, 2018
 #1
avatar+391 
+1

 All palindromes betwenn 100 and 500 are: \(101, 111, 121, 131, 141, 151, 161, 171, 181, 191, 202, 212, 222, 232, 242,\)\(252, 262, 272, 282, 292, 303, 313, 323, 333, 343, 353, 363, 373, 383, 393, 404, 414, 424, 434, 444, 454, 464, 474, 484, 494\). These are \(40\) numbers.

 

- Daisy

 Aug 31, 2018
 #2
avatar+100569 
+1

Thanks, Daisy....here's another way to do this  :

 

We  have 4 choices for the leading digit...and for the second digit, we have 10 choices....the last digit is the same as the  leading digit....

 

So....4  * 10  = 40 palindromes  between 100 and 500

 

cool cool cool

 Aug 31, 2018

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