They contact you on linkedin making you think that they are contacting you for a specific opening, you then go through an phone interview and ask you to answer silly math questions. They don't actually have roles for which they contact you for. Their goal is simply to keep interview as many people as possible to feed their database and reject the 99%. However, the issue is the 1% does not mean that those are the best candidates by any means. All it takes is to be quick at googling their silly math question so that you give them the right answer. A total waste of time.