Originally Posted by mickeycrimm View Post
Which die is showing the 2? The red die or the green die? That is the crux of the problem. You don't know which die is showing the two. So none of the 11 possible combinations can be eliminated.
It doesn't matter which die is showing a two.

Let me repeat that: given the problem, that there are two dice in the cup, it doesn't matter which of the two dice in the cup is showing a 2. This is why the dice are in a cup.