求“达到某种要求就结束”的问题的概率时,由于结束的情况不一样,常没有统一性,要分别考虑,比较麻烦,也容易“重”或“漏”.若用“虚满”法:即达到某种要求,还“虚拟”地继续下去,到最后再求它的概率,往往有统一性,这样处理常常简明快捷.问题1甲、乙进行一场乒乓球比赛,采用七 When seeking the probability of “problem to end when certain requirements are met,” there is often no unity due to the end of the situation. It is necessary to consider them separately and it is more troublesome. It is also easy to “heavily” or “leak”. Law: that is to achieve certain requirements, but also “virtual” to continue, finally to seek it again, there is often a unity, this treatment is often concise and quick. Question 1 A, B for a table tennis game, using seven