Decent reduction excluding the RR box though and a proof that it's irrelevant.
Luke Long
Close. It's either 100% green for the first green ball, 100% green for the second green ball (both in the first box) and 0% for the last green ball. Add those probabilities up and you get 200%, divided by three balls is an average chance of 66% or two thirds.
Nathaniel Cook
No, if you pull a green ball then there is only one ball left in the box. If the original box was (GG) then the remaining ball will be G. If the original box was (GR), then the remaining ball will be R. Since the (RR) box is irrelevant, there are only two possibilities left. One is G and one is R, therefore, 50% chance for G.
Jonathan Ramirez
If the first ball is green the there are only 2 boxes out of the 3 which have green balls then it's a 50/50 chance.
Andrew Davis
No, because it's more likely that you pulled G from GG in the first place rather than GR