I'm posting out of frustration! I'm stuck on the final PREFRONTAL CORTEX ASSESSMENT with the 3D cube and it's bugging the heck out of me.
Three separate times I've solved the cube up to the final two pieces, 25 & 26 and they were around the wrong way. Despite much fiddling I couldn't get them around the right way without messing up other pieces. Here's my solving method:
1. Shuffle everything around so I've roughly got 1-9 in the first layer, 10-18 in the seond layer and 19-26 in the third layer.
2. Put the first layer in correct numerical order from 1-9.
3. Put the second layer in correct numerical order from 10-18
4. Put the third layer in correct numerical order from 19-26 - although failing miserably on this step.
I skim read a bit about the 2D 15 piece variant of this puzzle:
http://en.wikipedia.org/wiki/Fifteen_puzzle
This indicates that some random configurations are genuinely impossible. Have other people found that sometimes they just can't solve the final 2 pieces and need to re-set the cube to get another configuration? Considering that there actually is a re-shuffle button, I have to assume that unsolvable configurations were anticipated by the designers.
Is there any rapid way to identify the configuration as unsolvable without having to spend 30 minutes getting to that final point?
Sad face.

Posted: Wed Jul 11, 2012 6:01 pm