Copyright © University of Cambridge. All rights reserved.

'Gridlock' printed from

Show menu

See all short problems arranged by curriculum topic in the short problems collection

If the square is completed with the letters A, B, C, D and E so that no row, column or either of the two main diagonals contains the same letter more than once, which letter should replace the asterisk?
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.