The principle of drawing lots comes from the total probability formula, which means that the order of drawing lots has nothing to do with the probability of winning lots.
10 test lottery, 4 difficult to sign, 3 people to participate in the lottery (not put back), A first, B second, C finally find the probability that A is difficult to sign, A and B are difficult to sign, A is difficult to sign, B is difficult to sign, A, B and C are difficult to sign.
Introduction of customer points
Customer points refer to the manifestations related to the cooperation degree of core business set by merchants in order to maintain customer relations. Customer points can directly reflect the close cooperation between customers and businesses. The higher the score, the closer the relationship between merchants and customers, and the greater the feedback from merchants.
This form of expression has been widely used in communication, banking, aviation, supermarkets, member service institutions and other industries, and more and more small and medium-sized enterprise customers also use this form to manage customer relationships. There are various forms of customer points, such as credit card points in the banking industry and mileage points in the aviation industry.