SolarCity Technical Project Manager interview questions

Initially contacted by Solar City recruiter via email, followed by recruiter phone screen and manager phone screen. On-site interview consisted of seven 30-minute 1:1 interviews with prospective managers, their director, and staff that interacted with this role. The first interview included math questions (below). The other interviews were more directly related to the position. I almost gave a neutral experience rating, but the reason for the negative rating is two-fold. First, I was informed of the interview late in the afternoon for an interview the next day. With 7 interviews, this took the bulk of the next day. I did state in the week prior that I would be available, but to be informed the evening before is still a little discourteous. Scheduling for the phone interviews were also last minute. Second reason is that I didn't know what position I was interviewing for until the 2nd or 3rd interview, when that particular interviewer had to call to find out himself. During the phone screen, the hiring manager mentioned interviewing for a hardware PM position under a different manager. I passed this on to the recruiter, who (strangely) kept asking me for next steps - didn't understand why the recruiter wasn't getting direction internally(?). When I actually showed up for the on-site, I wasn't sure which position was in play. And, in hindsight based on the questions, I think most of the interviewers weren't aware either. All of it together just gave me the sense that they fly by the seat of their pants and there's a lot of confusion. I'm still not entirely convinced that the recruiter didn't contact me in error, misunderstanding my background.