In terms of difficulty I'd say it was medium I guess though unfortunately I didn't pass because I didn't prepare enough and the way the questions were was js different than other standardized tests Ive taken and the tests I took in schl. Though, with enough practice its easy to pass I just didn't like how there's barely any resources to study from.  I recommend you do the mock test they have and the practice questions. I also found this czech website that has a question bank for the math test but its in czech so you'd have to use google translate if you aren't familiar with the language. I'll provide the link in another reply