Copyright © University of Cambridge. All rights reserved.

'Weekly Problem 46 - 2010' printed from http://nrich.maths.org/

Show menu


How many ten-digit numbers are there which contain only the digits $1$, $2$ or $3$, and in which any pair of adjacent digits differs by $1$?
 
 
If you liked this problem, here is an NRICH task which challenges you to use similar mathematical ideas.  
 
 

This problem is taken from the UKMT Mathematical Challenges.

View the previous week's solution
View the current weekly problem