Each of the triangular numbers that are below 1000 is written on a separate card. Some of these cards are then placed in a circle so that, viewed from the center, the right-hand digit of each card matches the left-hand digit of the card to its right. No tricks are used such as turning a card upside-down.

What's the maximum number of digits that can appear on such a subset of the cards?

 

 

all palyndromic numbers must be in:

   378 861 153 351 105 55 595 561 171 136 66 666

12 numbers, total  34  digits

Posted by Ady TZIDON on 2008-01-09 22:41:30