It's not my failure, it's yours.... you need to prove me wrong...
But since I don't have anything better to do... well, I have better things to do but I decided the window cleaning can wait... lol...
Regardless of the first 4x4 weighing, you have 4 in a control group. You have to use that. But not all of them, just 3 and move the others around.
Move around 3 marbles on ur 2nd turn. Based on your control group. That will give you the final answer on the 3rd try, with 1x1 marbles.
If the first 4x4 doesn't balance that leaves you with 8 marbles with one in it that's either heavier or lighter... you can move 3 marbles around but there is no way a 3x3 weighing will leave you with 1x1 that will also tell you if the odd marble is lighter or heavier... 8-6 = 2.. so you could be left with two marbles, one of which is lighter or heavier..
As I said, I wouldn't mind being proven wrong but I doesn't look like that's going to happen...
In memory of Pumpkins