Question

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?

Answer 1

Given that 18 mice were placed equally in two experimental groups and one control group

i.e. 3 groups

∴ The required number of arrangements

= `"Total arrangement"/"Equally likely arrangements"`

= `(18!)/(6!6!6!)`

= `(18!)/(6!)^3`

Hence, the required arrangements = `(18!)/(6!)^3`