There is a question about frequency and probability in the first volume of ninth grade mathematics. I can't understand the fourth question in Exercise 6.3 after class, and each teacher's answer is different. Try to find a positive solution! 1/2 * 1/4 = 1/8

In this way, if you turn out blue or green for the first time, you will fail, so the probability of not being eliminated for the first time is 1/2.

The second time, according to the results of the first time, all the colors except blue or green will be eliminated, so the probability of not being eliminated is 1/4.

These two events are independent of each other, so the multiplication rule is used.

The winning percentage is 1/8.