The probability of winning by changing boxes is high, which is 2/3. The probability of winning the prize without changing boxes is 1/3. Consider this: if you won the prize without changing the box, and you have chosen the box where the prize is located, then the probability is that you chose the prize among the three, and the probability is naturally1/3; If you change the prize, that is to say, you originally chose an empty box, and the probability of two empty boxes is 2/3. The latter can also be considered as follows: the whole activity will be divided into two parts at the end: the constant prize winning and the variable prize winning (because there are only two boxes left, but the probability is not 50/50, because conditions permit), so the constant prize winning is 1/3, which is naturally 65438.