It's selfish not to contribute to group efforts.
Rose is in a work group at school and their assignment is due at the end of the period.
Rose wants to get a good grade.
Rose puts in her best effort and contributes all that she can to the group's project.
Rose believes that if she lets the rest of the group do the project without her that she will just inherent a good grade.
The group and Rose all receive a good grade on their project.
While the teacher does give the group a good grade for their efforts it is noted that Rose did not contribute, and she is assigned extra homework.