Copyright © University of Cambridge. All rights reserved.

'Weekly Problem 20 - 2006' printed from

Show menu

Card with threaded string

A single piece of string is threaded through five holes on a piece of card. One side of the card is shown in the diagram above. Which of the diagrams below could represent the pattern of the string on the reverse of the card?
Five different cards showing threading

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