Brain Game: The Two Spirals


I strive to use original creations whenever possible for the Brain Game, but occasionally, I stumble upon an old challenge - often a visual one - that's worthy of reintroduction. Today’s Friday Free-for-All is one of those, and it comes from Martin Gardner’s 1975 book Tantalizing Teasers. Enjoy!

One of these spirals is formed with a single piece of rope that has its ends joined. The other is formed with two separate pieces of rope, each with joined ends.

Can you tell which is which by using only your eyes? No fair tracing the lines with a pointer!

Here is the SOLUTION.


The image on the LEFT is the single rope; the one on the RIGHT is two ropes.

Have a great weekend, everyone!