I don't know about other tests, but I have to say that I have taken a couple of language and translation tests which only took me a few minutes (maybe 8, not as fast as 5) to run through the questions and complete on the first attempt - and got in top 10% = even a '1st place' sticker - not because I am a genius but because they were ludicrously easy for a native speaker of English. So it can happen - if you are a fast reader.
It's all about the experience. I have 3 years of working experience as PHP Developer and I have worked on many complex portals like real estate and Food Delivering system. And so I thought to start working as freelancer with my old profile and when I started giving the test, it was like I know each and every answer, In fact, the question seemed to be so familiar that I was giving answers were so quickly and that I have finished in 3 min and place 1st rank with 4.95.