用概率树图法求解事件发生的概率

Using Probability Tree and Graph Method to Solve the Probability of Event

求事件发生的概率时,首先按事件先后发生的顺序画出概率树图,在概率树图上注明各个事件发生的概率,然后沿事件的终点重返始点,再利用概率的乘法公式和概率的可加性,即可求得事件发生的概率.

This article presents a method to solve the probability of event named probability tree and graph method. First, draw the probability tree and graph according to the sequence of the events, then mark the probability of every event on the graph, and then go back from the end point to the start point, at last the probability can be solved by using the multiplication formula and the addible attribute of the probability.