>>51521In this case, 50/50. Unlike other probability problems like Monty Hall, you're not going strictly off your odds to get a gold in the first place. You may have had a 2/3 chance to get a box that contains gold, but either way, it happened.
There are only two boxes that contain gold, and you picked a gold ball. Thus, there are only two possibilities; you picked box 1 or 2. If you picked box 1, you'll get another gold, and if you picked box 2, you won't. 50/50 shot.
