Hi Paola,

in addition to what mentioned by Carlos, I would recommend you the following:

• Commit to a time for each question, and go on if you surpass that time. If you do not set discipline, you will end eating too much time for some questions (these tests sometimes are actually structured to have some questions it is better to skip and review at the end). If time and test allows, you can then go back to the questions at the end.
• Practice a lot of math before (GMAT or online resources from Victor Cheng and/or PrepLounge)
• Use elimination process when in doubts
• Practice graph interpretation
• Practice quick reading and quick understanding of key information only
• Remember there are no penalties in the test, so you should try to answer all the questions

The best practice you can have is doing the higher number of tests you can find online; besides the 3 on McKinsey website, you should find additional 3-5 that you can buy online (or simply ask an expert if they can provide them and book a session – many of us have samples available. In this way you would get both the tests and a session).

You can also find some additional tips from Vlad at the following link:

https://www.preplounge.com/en/consulting-forum/i-have-my-mckinsey-pst-in-another-3-days-i-have-a-basic-idea-of-the-test-please-anyone-help-me-how-to-crack-it-with-only-3-days-preparation-609#a1226

Best,

Francesco