Читать книгу Statistics and Probability with Applications for Engineers and Scientists Using MINITAB, R and JMP - Bhisham C. Gupta, Irwin Guttman - Страница 119

The problem of computing probabilities of events in finite sample spaces where equal probabilities are assigned to the elements reduces to the operation of counting the elements that make up the events in the given sample space. Counting such elements is often greatly simplified by the use of a tree diagram and the rules for permutations and combinations.