At first I wanted to put this in ‘Indecorum’ which is doubling as a ‘Fun and Games’ section, but this is a great followup to the IQ Test.

Towers of Hanoi is a game of recursion or the skill and logic to find patterns if you don’t know what recursion is. Don’t place a big layer on a small layer or you’ll crush the cake.

Number of moves = 2 ^ (number of layers) – 1 :: 3 layers : 2 ^ 3 – 1 = 7 moves

It took some work, but I got it! No, the image isn’t photoshopped, Michael.

didcha do it in (2^7)-1 = 127 moves? i did it in just over 5 minutes after thoroughly confusing myself as to what i was trying to move several times…

Pressing the solve button is fun…

The trick is to decide with disk you want to move to which post. Calling the posts A, B, and C left to right. What you are really trying to do is move everything off the bottom disk, then move the bottom disk and move everything back onto it. So to move 7 disks, you move 6 disks, the last disk and then those same 6 disks again.

A trick if you lose track of where to move what:

Select the disk you wish to move (say from B to C). If there are an odd number of disks above it, move the top disk away from the target pole, in this case A. If there are an even number of disks above the disk you’re trying to move, start by moving the top disk TO to target pole, C.

You can really see how this happens if you start with 3 or 4 disks.