McKinsey PST: 9 top preparation facts and tips December 28 2014

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The McKinsey Problem Solving Test is among the most difficult standardised tests you will likely take in your lifetime. It is therefore worthwhile spending time understanding the basics of the test and learning preparation techniques from those who have succeeded. Here are the nine things you need to know about the test:

1. 26 questions

The PST is a pen-and-paper test used by McKinsey after screening CVs, and before the first round of case interviews. While it is designed to test your numerical computation and logic skills, it is not designed to test either your memory skills or your business knowledge as outlined in McKinsey’s coaching guide. 

The McKinsey PST is composed of 26 questions distributed over three different business cases. Each business case refers to a company or organisation that is facing a challenge and that has hired you to help them find a solution. Challenges can go from profitability issues to decisions about whether or not to enter a new market.

Questions will mainly fall under two categories: maths and logic. Examples of questions include: “Which of the following statements best describes the thoughts of the CEO?” or “Based on the data provided in Table 1, which of the following statements is a valid conclusion?” If you haven’t already done so, you can download the IGotAnOffer Free McKinsey PST as well as the McKinsey PST sample tests.

McKinsey does not test your business knowledge per say with its Problem Solving Test. However, being familiar with some basic business terms will help you feel more confident and allow you to understand certain questions quicker than other candidates. We have put together the video below to help you master these essential business terms:

 

 
 

2. 60 minutes

Everyone would probably succeed at the McKinsey PST if they were given an unlimited amount of time to answer each question. What makes the Problem Solving Test such a difficult challenge is that you only have 60 minutes to answer 26 questions. That’s about 2 minutes per question and managing your time efficiently is therefore key to succeeding.

In certain offices, non-native English speakers are given an extra 10 to 15 minutes to take the test. You should get in touch with your McKinsey HR representative if you are in this situation and do not know whether you are allowed this extra time or not.

In our experience, successful candidates overcome the time pressure they face when taking the PST by preparing for the test in three steps:

  1. They first acquire extremely confident maths skills by reviewing maths basics but also learning advanced techniques specifically helpful for the PST. This then enables them to not hesitate in maths during the test.
  2. They also develop a consistent answering technique. By approaching PST questions in a consistent way they build habits that enable them to be as fast as possible even under the pressure of the actual test.
  3. They take PST tests multiple times to get used to the type of questions that are frequently asked in the PST. As a consequence, question types that are regularly found in the official Problem Solving Tests do not surprise them.

These are the three pillars around which the McKinsey PST Training Programme is articulated. Since we launched this programme, more than 90% of candidates who used it succeeded at the PST compared to the average 33%. We will look into these aspects in more details in parts 7 to 9 of this article.

3. 33% of successful candidates

Every year about 200,000 candidates apply to McKinsey. The firm’s recruiting process is designed to identify the top 1% of candidates – but what skills is McKinsey looking for?

McKinsey recruiters use the Problem Solving Test to evaluate your maths and logic capabilities. Consultants use these skills extensively and the test helps the firm understand how you think, how you analyse large quantities of data and how you interpret it.

You may wonder why McKinsey needs such a test to assess these skills given it also gives candidates case interviews. There are two main reasons.

First, the PST is a standardised test and it therefore enables McKinsey to compare candidates on a like for like basis. Comparing the performance of two candidates on case interviews can be hard because they might have had different interviewers, different cases, answered the case differently etc. On the contrary, PST results directly show if the maths and logic skills of candidate A are likely to be better than the ones of candidate B. This can simplify the hiring decision process a lot.

Secondly, the Problem Solving Test is a cost effective way to streamline McKinsey’s recruiting process. More than 200,000 candidates apply to the firm every year and it would be extremely time-consuming and expensive for McKinsey employees to interview all of them. We estimate that out the 200,000 candidates, about 65,000 get invited to take the McKinsey PST and that 33% of them succeed at the test. It is therefore also an efficient way to short list candidates for the case interviews.

4. 70% cut-off score

McKinsey does not communicate the exact cut-off score for its Problem Solving Test. At IGotAnOffer, our best estimate is that the cut-off is about 70%. This is based on our experience of successfully passing the test, as well as on conversations with hundreds of successful candidates over the past few months. In either case, people who passed the test consistently scored above 70% during the last stages of their preparation AND performed well on the day. This means that on a 26-question test, you need to get at least 19 questions right in order to succeed.

There are a couple of things worth knowing about this cut-off score.

First, whether or not you succeed at the test only depends on YOUR score. It does NOT depend on how well other people have done at the test. If all the candidates in your PST session score higher than the cut-off score, all of you will progress to the next round of interviews. The outcome of the test therefore fully depends on you, which is a great incentive to do you absolute best at the test. 

Secondly, scoring VERY high at the PST can actually be a great strategy to be hired by McKinsey. A lot of candidates think that scoring about 70% will be just enough to get them to the next round of case interviews. However, your PST score will be used in later rounds of the recruiting process to decide if you will be made an offer or not. If in the final round you did as well as another candidate but only one position is available, McKinsey will likely choose you over the other candidate if you scored much higher a the PST. Scoring 90%+ can therefore be a great way to set yourself apart and our experience shows it is feasible with sufficient preparation.

Finally, we are often asked how much time one should dedicate to preparing for the test. In our experience, most successful candidates spend about 30h or more training. There are actually fewer candidates capable of passing the test without training seriously than most people imagine. The vast majority of candidates who end up working at McKinsey are bright but also very determined and motivated people who invested time and effort getting into the firm.

5. No calculator, no scrap paper

As a consultant, you will regularly have to make mental maths estimates in client meetings and discussions. This is the main reason why you will not be allowed to use a calculator during the test. You might have thought that nowadays consultants would use their smartphones to make estimates in meetings, but they do not tend to. In our experience this is to avoid disrupting the flow of the meeting and also a little bit to try to impress the client!

In addition, scrap paper will also not be allowed during the test. You will therefore have to carry out all calculations on the white spaces in your PST booklet. McKinsey likely forbids scrap paper for very practical reasons. It enables them to make sure no one has a chance to write down PST questions on scrap paper to bring them back home and distribute them to future candidates.

We therefore encourage you to take the McKinsey PST sample tests in real conditions: no calculator, no scrap paper and in 60 minutes. In our experience, training in these conditions will make sure you perform to your best on the day of the actual test.

6. Answer all questions

You should answer all McKinsey PST questions because there are no penalties for wrong answers. Indeed, every right answer gives you +1 point and every wrong answer 0 point. As a consequence, if you hesitate between two answers or are running out of time during the test you should select an answer at random. With a bit of luck, this will help to boost your score.

We also recommend that throughout the test you regularly write down your answers in the answer sheet that you will be provided with. This may sound obvious but some past candidates who trained with us forgot to do that when taking the official test because of the stress. They had to fill in the answer sheet in a rush during the last one or two minutes of the hour and came close to failing the test as a result. We encourage you to save yourself this last minute moment of panic and fill in the answer sheet as you progress.

7. Develop confident maths skills

The McKinsey PST is a challenging test and a lack of preparation often prevents very capable candidates from getting into McKinsey. It is almost impossible to succeed at the Problem Solving Test without being able to perform mental calculations extremely quickly and accurately. This is essential because more than 50% of questions in the test involve maths.

It is common among candidates to have rusty maths skills when they start preparing. However, in our experience, successful applicants tend to dedicate energy to sharpen their mental maths and learn shortcuts at the start of their preparation. This small initial time investment seems to provide them with the confidence they need to perform computations quickly and accurately on the day of the test.

8. Acquire a consistent answering method 

Successful candidates tend to develop a structured and consistent approach to answering PST questions over the course of their training. Approaching each and every PST question with the same method enables candidates to build habits. On the day of the test, these habits make a huge difference as they help to reduce stress and save a lot of time. 

At IGotAnOffer, we were frustrated by the lack of high quality material and information available when we were preparing for the PST. After trying different approaches to answer McKinsey PST questions, we finally identified a structured and consistent answering method that produced a step change in our score and allowed us to pass the test. We then set out to share the “IGotAnOffer” method with future generations of candidates.

 Having a consistent answering method may sound a bit mechanical at first, but more than 90% of the candidates who have trained with us and used our method have passed the PST so far. Some of the best universities around the world including Harvard also recommend using our approach.

9. Practice on sample tests

Once having settled on a consistent answering technique as well as identified frequent PST questions, you should practice as many tests as possible until you are confident you will score 70% or more. When practicing, we encourage you to study your mistakes. A lot of candidates overlook this part of their training and just focus on taking PSTs. But making sure you understand why you failed at certain questions will ensure you progress quickly and steadily.

There are not a lot of opportunities to practice for the PST so you should try to make the most of every test. McKinsey provides 3 sample PSTs for free and in order to help candidates train on more sample tests, we have also created additional PST sample tests. To organise the time you have left before the day of the test, you can have a look at the 2-week preparation plan we have put together for you.

If you still have doubts or questions about how to prepare for the PST after reading this article, feel free to leave a comment in the section below, we will do our best to reply promptly.

Additional resources

Candidates from the best universities around the world use our McKinsey Case Interview Training ProgrammeFree McKinsey Case Interview PrepMcKinsey PST Training ProgrammeFree McKinsey PSTBCG Potential Test Training Programme and Free BCG Potential Test. Some races are worth the extra effort - let's get started!

The IGotAnOffer team

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