等可能概率问题是学生理解概率概念的重要模型,对其理解和计算大都要通过计算出基本事件个数,怎样正确看待和计算基本事件个数便成为该类问题的难点,本文将等可能概率问题建立两种模型———摸球模型和球放入盒子模型,并规定相应的两条原则,使问题得以顺利解决.等可能概率问题 Such probabilistic problems are important models for students to understand the concept of probability. To understand and calculate them, we must calculate the number of basic events. How to correctly view and count the number of basic events becomes a difficult point for this type of problem. This paper will wait for probable probability. The problem is to establish two models—the ball model and the ball into the box model, and define the corresponding two principles so that the problem can be resolved smoothly.