Don't bother. This company will ask you to do an assessment for 5 different projects (a brochure, a T-shirt design, a stationery header template, a PowerPoint template, and a photo touch-up). Each project will take you, on average, 1.5 hours to complete. So, they are essentially asking you to do 8 hours of FREE work for them and then provide the working files.
Furthermore, they don't have the decency to provide feedback if you don't move on to the next round of the interview. What would take them 5-10 minutes to write an email at most, whereas you did 8 hours of FREE work for them, and they don't have the decency to provide that.
The point is, they are not worth the time, and they will happily exploit designers. It goes to show that they would probably exploit their workers. Don't bother interviewing with them.