a magician will perform her magic tricks omly if there are at least 9 people in the audience

. Otherwise, she will cancel the show. This is because the magician's tricks often involve audience participation and the energy of the crowd is important for the success of the performance. Additionally, a larger audience provides a better atmosphere and increases the overall entertainment value. Therefore, having at least 9 people in the audience is a necessary requirement for the magician to perform her magic tricks.