Wood Mackenzie interview questions

I applied this job and was scheduled a presentation after talking to HR. The presentation is a little difficult to me just because it's a completely unfamiliar topic to me so I had to read a lot of academic paper to find all solutions to answer their questions. It's really weird that they wanted me to demonstrate math derivation in my presentation, although I still found them the math solution and everything they asked. The interview was terrible, the manager was nice and he was the one asked me questions. I found the whole interview team were not from technical education background so undoubtedly my presentation was boring to them (I also think so but that's what they asked me to do for the demo!!!). My suggestion is if you decide to ask interviewee give you hard math answers, you should also prepare to listen to what you desire.