question_answer

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

A)  \[\frac{181}{{{(6!)}^{2}}}\]               

B)  \[\frac{181}{{{(6!)}^{3}}}\]        

C)  \[\frac{180}{{{(6!)}^{3}}}\]               

D)  None of these