If I have a 3x3x3 cube and color it. Then I break it apart into 1x1x1 cubes. If I pick up a cube and see that it has color, what is the probability that it's edge cube.
My attempt:
Out of 27 1x1x1 cubes, 26 have color. Then there are 8 edge cubes on the top, 8 on the bottom and then 4 at the side. So the answer should be 20/26. Can someone confirm?
EDIT:
If consider edge cubes different from corner cubes, then it should be 12/26.