Which question types are there and what should I focus on?
What question types are there within McKinsey PST?
Overview of answers
As others have said, official McKinsey PST are very similar to the ones on the official site - e.g. https://www.mckinsey.com/~/media/McKinsey/Careers%20REDESIGN/Interviewing/Main/Problem%20Solving%20Test%20PDFs/practice-test-A.ashx
In general PST is quite different to tests for other companies as it includes 3 "cases" with a series of follow-up questions. These test both your logical/analytical skills, your ability to do quick maths (and take shortcuts/estimate where required), and your verbal reasoning skills (e.g. which statement best summarises the client's thoughts).
Where you focus depends on your strengths and weaknesses - PST can be a difficult test for different reasons (e.g. speed reading, doing maths quickly, verbal reasoning) - do a practice test, see what you found most difficult and then focus on that.
I'll give you a tip - The real PST tests are the exact same as the practice. Different content and figures but the format, question type, wording, style etc are all the exact same. If you are comfortable doing these you will find the test fine on the day you complete it!
You should look under the PST keyword here and you will see many more detailed posts about how to tackle and what questions to expect.
My best advice is to do the practice ones on the website 2 or 3 times....aim for 60-70%.
It's similar to the one on the official site.
I recommend the following:
1) Do 1 case from mck website in 60 min. Check your score. Target score is 22 out of 26 correct. If you do 17-18 correct you have great chances to improve in a week. If lower - you need a significant prep
2) Buy Viktor Cheng test prep program - best materials I've seen so far. Works also for express prep.
3) Do the 2nd test and check the score
4) Use other materials: GMAT IR and verbal parts, PST-like tests available online. The key thing - you should train to do them, fast
5) Do the 3rd test and check the results
P.s. in parallel train your math. Check exercises on Cheng website. Key things - multiplication of 2 digit numbers, operations with zeros and division (Learn division table, ie. 1/8 = 12.5%, 8/9 = 88%, Learn up to 8/9)