Originally Posted by mickeycrimm View Post
Let's color code the dice. One die is RED and the other is GREEN.

Combinations with at least a two in them:

Red 1, Green 2
Red 2, Green 2
Red 3, Green 2
Red 4, Green 2
Red 5, Green 2
Red 6, Green 2
Red 2, Green 1
Red 2, Green 3
Red 2, Green 4
Red 2, Green 5
Red 2, Green 6

Problem #1.

Our friend looks under the cup and says "At least one die is a two." What is the probability that both dice are 2's?

Why is the answer 1 in 11 and not 1 in 6? Because we don't have enough information to determine it is 1 in 6. All we know is that one of the dice is a 2.
You still don't get it, do you?

That's all the information you need to know to figure the answer is 1/6. There are only two dice. If at least one is a six you know that 2 dice - 1 die = 1 die and one die has six faces on it, one of which is a 2. Is that really so difficult?

Really, is it?

Regnis gets it. Maybe he can explain it better than I do.