there are several free resources available that can help you practice and improve your skills. Here are a few options:

PrepLounge's Case Library: PrepLounge offers a wide range of case interview resources, including practice cases from top consulting firms like McKinsey, BCG, and Bain. You can find the case library here: [https://www.preplounge.com/en/management-consulting-cases]

Case Interview Examples: CaseInterview.com provides free case interview examples and solutions from various consulting firms. You can find McKinsey, BCG, and Bain case examples on their website.

Consulting Firm Websites: Consulting firms often provide sample cases or practice materials on their websites. You can visit the career or recruitment sections of McKinsey, BCG, and Bain's websites to see if they offer any free resources.

YouTube Channels: There are several YouTube channels dedicated to case interview preparation. Some popular channels include CaseInterview.com, Victor Cheng, and Consulting Guru. These channels often provide tips, frameworks, and practice cases that can be helpful for your preparation.

Remember, while these resources are free, it's important to practice consistently and simulate real case interview conditions as much as possible. Consider timing yourself, working through cases with a partner, and seeking feedback to enhance your performance.

I hope these resources help you in your preparation for McKinsey Solve, BCG Online case, Playmetrics, and Bain's online assessment