Although correlated, high math skills aren't a great proxy to the desired analytical skills you'd want. It is easily gamed with rote memorization if this test was discovered by an applicant pre-interview, as they would just prep for it (in which case, it ceases to be a good metric).
Yes, but it’s still pretty common. When I was interviewing for my first job, they were much more impressed with a couple of math puzzles I solved than my actual programming ability.
It was 45 mins of math.
Questions ranging from simple algebra to probability theory to physics. And I was applying for an embedded systems position.
Boy was I glad that I was good at that kind of math.