Privileges : modify dir/file owner by other that's not owner

i need to do the following operations in solaris 10:

1.change owner and group owner for files which are not owned by the current user and user group
2.to can delete files in the /tmp directory which are not of the current user
3. allow to a standard user the deletion of files in the /tmp directory which are owned by root

thanks for help!

This sounds like homework. Is it?