Current location - Training Enrollment Network - Mathematics courses - A question about mathematical expectations, for example, there are five kinds of colas in different packages. How to calculate the average number of bottles of coke needed to buy all the packages?
A question about mathematical expectations, for example, there are five kinds of colas in different packages. How to calculate the average number of bottles of coke needed to buy all the packages?
5/5 + 5/4 + 5/3 + 5/2 + 5/ 1

Five kinds of cola, it takes an average of 5/5 bottles to get one of the five kinds.

Five kinds of colas, it takes an average of 5/4 bottles to collect one of the four kinds.

Five kinds of cokes, it takes an average of 5/3 bottles to get one of the three.

Five kinds of colas, it takes an average of 5/2 bottles to collect one of the two.

Five kinds of colas, it takes an average of 5/ 1 bottle to collect one of them.