中文摘要：

研究了一类需要预测长期趋势的古典概型问题,其将来的状态只与现在的状态有关,与以前的状态无关.分别应用全概率公式和Markov链,给出该类问题的两种不同解法.

英文摘要：

We study a kind of classical probability problems whose future states are associated with the current state but the previous states. By the total probability formula and Markov chain, respectively, two different approaches to the solution of problems are presented.