Gaokao 2025 - Ping Pong Probability Challenge! 🏓

Описание: This was the second last problem on the Gaokao 2025 that took place several weeks ago (National Exam 2 - 全国二卷).
It's a lovely problem. Parts (1) and (2) are quite standard binomial probability questions, while part (3) requires a deeper level of understanding.

It was also given in the question that the probability p is between 1/2 and 1 (this got lost in translation 😅).