Copyright © University of Cambridge. All rights reserved.

'Magic Octahedron' printed from

Show menu

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

The diagram show the net of a regular octahedron.

In a magic octahedron, the four numbers on the faces that meet at a vertex add up to make the same total for every vertex. If the letters $F, G, H, J$ and $K$ are replaced with the numbers $2$, $4$, $6$, $8$, and some other number, in some order, to make a magic octahedron, what is the value of $G + J$?

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.