18 mice were placed in two experimental groups and one control group, with all groups equally large. In how many ways can the mice be placed into three groups?

Solution:

As per the question,

18 = No. of mice

3 = No. of groups

As the groups are equally large,

No. of mice in each group mice

No. of ways of placement of mice

The placement of mice for each group

As a result, the number of ways required