Calculation formulas of probability theory c and a
Calculation formula of 1C
C represents the number of combination methods.
For example, c (3,2) means to select two objects from three objects, total * * *, and there are three methods, namely, A, B and C (three objects are different at the same time).
Calculation formula of 2A
A indicates the number of arrangement methods.
For example: n different objects, to take out m (m
You can also think of it this way: the first one has n choices, the second one has n- 1 choices, the third one has n-2 choices, and the m-th one has n+ 1-m choices, so the total * * arrangement method is n (n-65438+).
Note: in specific topics, it depends on whether the topics need to be arranged or combined, that is, whether the monomers need to be in order, and A is needed instead of C.
3 probability theory
Bayesian theorem Probability theory or probability theory is a mathematics that studies randomness or uncertainty. More precisely, probability theory is used to simulate the situation that experiments will produce different results in the same environment. Typical random experiments include dice, coin toss, poker probability theory and roulette game.