SIMULATION - Create a catalog under /home named admins. Its respective group is requested to be the admin group. The group users could read and write, while other users are not allowed to access it. The files created by users from the same group should also be the admin group. 

See explanation below.

# cd /home/ # mkdir admins / # chown .admin admins/ # chmod 770 admins/ # chmod g+s admins/