Simple probability problem

In combinatorics, the rule of sum or addition principle is a basic counting principle. Stated simply, it is the idea that if we have A ways of doing something and B ways of doing another thing and we can not do both at the same time, then there are A B ways to choose one of the actions. In combinatorics, the rule of product or multiplication principle is a basic counting principle (. the fundamental principle of counting). Stated simply, it is the idea that if there are a ways of doing something and b ways of doing another thing, then there are a · b ways of performing both actions. #Genetics #ruleOfSum #ruleOfMultyplication #probability #statistics