考虑闰年条件的生日问题
Birthday Problem Considering Leap Year Condition

很多概率论教材中有关计算存在两人相同生日概率的问题，也把解决这样的问题作为训练巩固学生理解等可能概率的重要手段。文章讨论了含有闰年情况的相同(不同)生日问题，通过分组方式给出了不同情况下生日不同的概率，并提出了一种非等可能放球的新的盒子模型，丰富了盒子模型理论。
Many probability theory textbooks have the problem of calculating the probability that two people have the same birthday, and they also take solving such problems as an important means of training and consolidating students’ understanding of possible probabilities. This paper discusses the problem of the same (different) birthdays with leap years and presents a new box model with unequal possibilities of putting the ball, which enriches the box model theory.