Difference between revisions of "1991 AHSME Problems/Problem 17"

(Created page with "A positive integer <math>N</math> is a ''palindrome'' if the integer obtained by reversing the sequence of digits of <math>N</math> is equal to <math>N</math>. The year 1991 is t...")
 
Line 6: Line 6:
  
 
How many years in the millenium between 1000 and 2000 have properties (a) and (b)?
 
How many years in the millenium between 1000 and 2000 have properties (a) and (b)?
 +
{{MAA Notice}}

Revision as of 13:53, 5 July 2013

A positive integer $N$ is a palindrome if the integer obtained by reversing the sequence of digits of $N$ is equal to $N$. The year 1991 is the only year in the current century with the following 2 properties:

(a) It is a palindrome

(b) It factors as a product of a 2-digit prime palindrome and a 3-digit prime palindrome.

How many years in the millenium between 1000 and 2000 have properties (a) and (b)? The problems on this page are copyrighted by the Mathematical Association of America's American Mathematics Competitions. AMC logo.png