- Probabilities that are dependent are multiplied
- Probabilities that are independent are added
\(Probability(X) = \frac{Number Of Combinations With X}{Total Number Of Combinations} \)
\(N = {t \choose n} = \frac{t!}{(t – n)! \cdot n!} \)
- t = total number of occurrences, n = number of occurrences
\(P = {t \choose n} \cdot c^n \cdot (1-c)^{t – n} \) (with putting back)
- t = total number of occurrences, n = number of occurrences, c = probability on single occurrence
\(P(X) = \frac{{x \choose a} \cdot {y \choose b} \cdot {z \choose c}} {t \choose n} \) (without putting back)
- t = total number of occurrences, n = number of occurrences, t = x + y + z, n = a = b + c