Number of new female swimmers is 12 and number of returning female swimmers is 30.
A) As each practice team must have the same number of new and returning female swimmers, so for finding the greatest number of practice teams, we just need to find the GCF(greatest common factor) of 12 and 30.
![12 = 2*2*3\\ \\ 30= 2*3*5](https://img.qammunity.org/2019/formulas/mathematics/college/9kgxpgb7wwpgy0up9vm5k8kz2ituig6ttw.png)
As the common factors are 2 and 3 , so the GCF will be:
![2*3=6](https://img.qammunity.org/2019/formulas/mathematics/college/xlejre3vk3o0nuar9ntg53hqfskj823xqk.png)
Thus, the greatest number of practice teams the coach can make using every swimmer will be 6.
B) As there are total 6 practice teams, so in each team.....
Number of new female swimmers
and
Number of returning female swimmers