Soo I had a job interview today. Which went very different than I expected. It was a junior position which required c++ basics. I applied and I got the interview. Everything went fine and at the end they said they will send me a task to my email address and I should let them know if I have any questions and send them the solution. I got home and it was something entirely different. On my email I got sent a hard math problem which I do not even know what it is about. It contains a summation sign and some formulas I have never seen in my life.

So I wanted to ask a question are all companies like this? And will I require to learn advanced mathematics to even get a position as a software developer?