A dance studio has 40 nine-year-old children sign-up for ballet class. The studio owner decides to divide the children into two nine-year-old ballet classes: Class Alpha and Class Beta. If the studio owner wants each child to have a fair chance of being placed in either class, which of the following describes a method that cannot be used to help the studio owner place the children?

This question cannot be open. It has to have a set of answer choices. There are many ways to make the division fairly and many to make it unfairly.

The fair divisions are supposed to be random, while the unfair division are those that are not random.

Some examples of not fair division are:

1) Separate the group by sex, this is one group of males and one group of girls.

2) Separate by weight

3) Separate by size

4) Separate by month of birth.

This should help you to find which of the statements from your list reflects a non fair division.