It's a scam that is run to crowdsource ideas. First HR will source your profile and they will give a real time case study with their burning problems today (2 cases) and ask you 5,6 questions. We will be provided with 5-7 days to solve for it. It will take 40 hours of your time if you want to answer all the questions.
Once you submit it, the next round is just a brainwash to understand the solutions better and irrespective of how well you do in these two rounds , they will send out a rejection mail quoting some silly reasons.
This is a new type of scam in the industry and it is embedded in their culture. Do not fall for it and waste your time.