# Consultancy Case Study Interview Question

McKinsey interviews are among the hardest job interviews you will come across. The questions are difficult and specific to McKinsey and the interviewer can sometimes seem intimidating.

But the good news is that with the right preparation it can actually become relatively straightforward to succeed at a McKinsey interview. We have put together the ultimate list of facts and tips you need to know to maximize your chances of success.

**1. One in ten interview candidates get a job offer**

First, it is important that you understand the different stages of your interview process with McKinsey and your chances at each step. In most countries, McKinsey usesfour filters to select candidates:

- CV and cover letter screening
- McKinsey Problem Solving Test (PST)
- First round of interviews
- Second round of interviews

In arecent interview, Dominic Barton, McKinsey’s Global Managing Director, revealed that about 1% of the 200,000 candidates applying to the firm every year receive a job offer.

Assuming a 33% success rate at the four steps of the recruiting process described above, we estimate that McKinsey interviews about 21,000 candidates every year and that they extend a job offer to about 2,200 of them. If you have been invited to a first round interview with McKinsey, you therefore have a 10% chance of getting an offer.

- Filter 1 / CV and cover letter: 200,000 candidates
- Filter 2 / McKinsey PST: ~65,000 candidates
- Filter 3 / First round of interviews: ~21,000 candidates
- Filter 4 / Second round of interviews: ~6,800 candidates
- Job offers: 2,200 candidates

The good news is that the first and second round interviews are really manageable when you know what to prepare for. The first thing to focus on is really trying to understand what skills McKinsey is testing for in case interviews.

**2. Skills tested by McKinsey case interviews**

McKinsey uses case interviews to test three types of skills that are used by consultants in their daily job:

- Problem structuring and maths skills
- Creativity and business sense skills
- Communication skills

First, McKinsey already started testing your maths skills with itsProblem Solving Test. This skill will continue being tested during case interviews and you will be expected to perform mental maths both quickly and accurately. In addition, your interviewer will also ask you to solve the problem at hand in a structured way. In simple terms, that means you will be expected to solve the questions you are asked in a clear step-by-step approach that is easily understandable by your interviewer.

Second, McKinsey case interviews are designed to evaluate your business sense and creativity. That means your interviewer will assess your ability to come up with a range of ideas that make business sense to solve the client issue at hand. For instance, you could be asked to find innovative ideas for a restaurant to grow sales, or to decrease costs.

An important nuance is that interviewers will not assess your business knowledge per se. In other words, you are not expected to have any knowledge of the industry your case will be about. For instance, you could get a case about re-insurance and not know what the re-insurance industry is. This is perfectly normal. In these situations, your interviewer will expect you to ask questions about the industry and will help you understand its specificities.

The only expectation is that you know basic business concepts such as revenues, fixed and variable costs, etc. We have summarized the finance concepts you need to know for consulting interviews here.

Finally, your interviewer will also test your softer skills. This includes how you communicate your ideas and interact with others. Good soft skills are critical to deal with clients as a consultant and a lot of interviewees underestimate their importance. To put things simply, you should try to communicate your ideas in as a structured way as possible during case interviews and behave in a professional way.

Take a look at the following excerpt of one of our McKinsey live case interview videos to find out what a good, consistent approach to answering case interview questions sounds like.

**3. Differences between 1st and 2nd round interviews**

The second important thing to understand is the number of case interviews you will have and how they will differ. In most cases, you will have two rounds of interviews. The number of interviews by round may vary but it is usually between 2 and 4. In total, you will therefore have between 4 and 8 interviews before getting a McKinsey job offer.

First and second round interviews are similar in format and difficulty. However, your first round interviewers will usually be more junior than your second round ones. Associates (2+ years of experience) or Engagement Managers (4+ years of experience) usually lead first round interviews while the second round is led by Partners (10+ years of experience).

In theory, McKinsey takes into account your performance at both first and second round interviews when it makes the decision to make you an offer. However, in practice, your performance during the second round carries a bigger weight simply because Partners will have a stronger voice when the recruiting group will get together to make a final decision on your application. It is therefore particularly important that you do well at your second round interviews.

Let’s now look at how interviews are structured and help you prepare for each of the different sections. Your interviews will usually last between 45 and 60 minutes and consist of two parts:

- Personal Experience Interview – for 25% of the interview time
- Case Interview – for 75% of the interview time

Let’s first focus on personal experience interviews.

**4. Personal Experience Interview**

The PEI part of your interview will last about ten minutes. It is fairly different from a typical “CV interview” mainly because your interviewer will only assess you on a *single *topic. Interviewers at other firms tend to cover a large range of topics during a “CV interview” but that is not the case at McKinsey.

The good news is that the topics on which you will be assessed are very predictable. They are made relatively clear on McKinsey’s career website: personal impact, leadership abilities, entrepreneurial drive and problem solving skills. For instance you could be asked: “Tell me about a time when you led a group of people through a difficult situation” or “Tell me about a time when you had to solve an extremely difficult problem”.

Our recommended approach to prepare for these questions is to craft a story for each of the four skills McKinsey will test you on. You can then use and adapt these stories depending on the exact question your interviewer will ask. There are different structures you could use to tell your story but we recommend keeping it relatively simple:

- Context: start by giving the necessary context on the example you are using
- Problem: outline the problem you and your team were facing
- Solution: explain the solution you came up with to solve the problem outlined
- Impact: if possible, quantify the impact you had in solving the problem
- Lessons: finish by any lessons you might have learned in the process

There are two common mistakes candidates make when answering McKinsey PEI questions. First, a lot of candidates spend too much time on setting the context when telling their story. Second, some candidates forget that the question is about them. They should therefore focus on what *they* did, what *their *impact was on the situation they are telling their interviewer about. When you craft your four stories you should keep these common pitfalls in mind and try to avoid them.

For more details and example answers, you should read the following blog post on how to impress your interviewer when answering Personal Experience Interview questions.

**5. McKinsey case interview structure**

After thePEI question, your interviewer will then move on to the case interview.

In this part of the interview, you will be presented with a business case about a company facing an issue. For instance, your case could focus on an industrial facility facing a profit challenge, or a company that needs help to make a strategic decision on a new product. Cases are usually a simplified version of real projects your interviewer worked on in the past.

Your interviewer will tell you about the situation the company is facing and will ask you questions about the situation. She may also provide you with documents such as graphs and tables with figures about the company. You will be allowed to use scrap paper to structure your thoughts and perform calculations. However, you will not be allowed to use a calculator.

Most McKinsey case interviews use the following structure:

- Situation
- Framework question
- Quantitative question
- Creativity question
- Recommendation

First, your interviewer will introduce you to the company’s situation and the business problem they are facing. Then, the interviewer will ask you to identify the areas you would look at to solve the problem at hand -this is the framework question. You will then be asked to solve one or several quantitative questions that will help further investigate the problem faced by the company and draw some initial conclusions.

In addition, at some point during your interview, you will be asked a creativity question. These are usually open-ended question such as “what are the other areas the company could look at to increase its online sales?”. Finally, at the end of the case, your interviewer will ask you to make an overall recommendation for the company based on the analysis you have just carried out.

Although the format and order of questions may vary from one case to the next, you will almost invariably come across these types of questions during your McKinsey interviews and should therefore prepare for them. To find out more about the format of case interviews, you can download our Free McKinsey Case Prep product here.

An additional exercise we would recommend doing is to take a look at the different case interviews available on McKinsey's website. As you go through each case, you should try to map each question to the 5 types of questions we have listed above.

**6. Differences between McKinsey and other cases**

All consulting firms use case interviews during their recruiting process. But McKinsey interviews are different in two regards.

First, McKinsey interviewers tend to control the pace of the interview much more than other interviewers. They’ve got a list of questions about the case they want to go through with you and will take you from one question to the next. If they feel you spend too much time on one question, they might interrupt you and ask the following question. Some people call this “interviewer-led”case interviews. At other firms such as Bain or BCG, interviewers give you more control over the pace of the interview. Some people call this “interviewee-led” case interviews. The skills tested in both types of cases are the same but you should expect slightly different behaviours from your interviewers.

Second, there is a lot of competition to get into McKinsey, and your interviewer will probably challenge the quality and logic of your answers more than at other firms. That being said, interviewers are instructed to always be well intentioned and therefore will not try to “trip you up” or misguide you.

Let’s now walk through the skills you need to develop to be able to impress at these difficult case interviews.

**7. Develop confident maths skills**

It is almost impossible to crack case interviews without being able to perform maths calculations quickly and accurately. This is because every case interview at McKinsey includes quantitative questions and you will not be allowed to use a calculator to answer questions.

When you start preparing for case interviews, it is common to have relatively rusty maths skills. However, in our experience, successful candidates take the time to refresh their memories and learn a few maths shortcuts*at the start*of their preparation. This initial time investment provides them with the confidence they need to perform calculations confidently in case interviews.

We definitely encourage you to make this initial time investment. In fact, this maths preparation is the first step of the McKinsey Case Interview Training Programme we have put together. To help you refresh your maths skills, here are also a few mathsshortcutsyou should consider using.

**8. Acquire a consistent answering method for each type of questions**

As mentioned previously, McKinsey case interviews follow a pre-defined set of questions: situation, framework, quantitative, creativity and recommendation questions. It is therefore critical that you learn to quickly recognise these types of questions and that you develop a consistent method of answering them. Approaching each question with a pre-defined method will enable you to build strong*habits*. On the day of your case interview, these habits will make a huge difference as they will reduce your stress and save you a lot of time and mistakes.

At IGotAnOffer, when we were preparing for case interviews, we were frustrated by the lack of consistent method that existed to crack case interviews. We have therefore developed a method to consistently answer McKinsey case interview questions. After being successful at case interviews, we then set out to share this “IGotAnOffer” method with future generations of candidates through ourMcKinsey case interview programme.

Having a consistent method to answer different case interview questions may feel a little mechanical at first. But trust us, if you stick to a pre-defined method you will experience a step-change in your performance that will help you get a job offer at McKinsey.

**9. Practice out loud**

Another key element to succeed at case interviews is practicing in real conditions. If you can practice case interviews with a partner you should definitely do so, that will help you progress faster.

However, when you practice by yourself there still is something you can do to recreate case interview conditions: practicing out loud. While this may sound a little awkward at first, in our experience, candidates who have forced themselves to use this technique have progressed much faster than others.

When you practice out loud, you should both play the role of the interviewer and the interviewee. You should ask yourself the questions your interviewer would ask you and then answer these questions out loud as if you were in the interview.

The reason this technique works so well is that it forces you to practice communicating your answer to your interviewer. As mentioned previously, communicating in a structured and simple way is a key skill assessed by McKinsey. Developing this skill as much as possible will make a big difference on the day of the interview.

**10. Learn from every case**

Finally, the best candidates learn as many things as possible from every case they do. In our experience, it is much better to train on 20 case interviews and to learn a lot from them than to train on 40 and not learn much.

To ensure you make the most of each case you practice on, we recommend that at the end of each case, you write down what you have learned as well as the main mistakes you have made. After a few days you should then do the case again. This approach will enable you to make sure that you apply what you have learned and to ensure you are making progress.

**Conclusion**

McKinsey interviews are challenging because there is a lot of competition for the job, interviewers can be a little intimidating and there is quite a lot of ground to cover in your preparation. However, if you follow the tips listed above it is completely feasible to get a job at McKinsey.

In addition we have put together a McKinsey Case Interview Training Programme to help you land the job. Since we launched the programme at the beginning of 2016, **more than 80% of candidates who used it landed a job at McKinsey**. We know this because we give 50% of their money back to people who do not get an offer.

If you would like to learn a method to consistently crack the case you can get started below:

Free Case Interview Prep | McKinsey Case Interview Training Programme |
---|---|

**Any questions about McKinsey case interviews?**

If you have any questions about McKinsey case interviews, do not hesitate to ask them below and we will be more than happy to answer them. All questions are good questions, so go ahead!

**The IGotAnOffer team**

Photo: Ed Gregory / Stokpic

## Case Study Interview Examples: Questions and Answers

You will need to prepare for an interview where case study questions will be asked. While preparation is required for every job interview, extra time is required to adequately prepare for case study interviews.Providing an answer to a case study question involves much more than simply recounting the issues and problems set forth, it includes identifying the most important issues, employing sound and logical analysis, developing an action plan for addressing the problem(s) and making recommendations. Depending on the firms you're interviewing with, and the industry you work in, case study questions can be presented in verbal or written format, and address a number of topics.

In case interviews, it's not uncommon for interviewers to exclude important details when asking candidates to resolve hypothetical business problems presented. It's okay to ask interviewers for more information, and it's expected. They want to see if you can identify what information is important, and what is not.

Occasionally, interviewers provide no detail at all to test your analytical skills when adequate resources are unavailable. In these situations, it's okay to make assumptions, but they must be based on sound logic and analysis of information that is provided.

Interviewers asking case study questions are primarily concerned with how effectively you can analyze a problem, determine key factors, brainstorm ideas, and propose workable, pragmatic solutions that are supported by your analysis.

**Answering Case Interview Questions**

Where a specific framework for analysis isn't readily available or applicable, a general framework or analytical approach can be applied. The most important thing is that your approach to answering the case interiew question is structured and logical.

Regardless of the type of case you're presented, there will likely be a few main parameters and several factors that influence those parameters. The first thing you want to do is identify the parameters and factors, the then determine which are key to the case output.

For example, assume the case involves a company's declining profitability. From your initial review of the case information you determine the main parameters to consider are total revenues and total costs.

After defining the two main parameters, you'd then drill down further to the factors influencing each of the parameters you've identified. You determine the factors influencing total revenues are average price of goods sold and volume of goods sold. And for total costs, fixed costs and variable costs.

With both the case parameters and factors clearly identified you give yourself the ability to steer the conversation and begin to identify possible solutions. To identify areas of concern, you'll want to explore the history of the four influencing factors. At the end of your discussion with the interviewer you may determine that it's rising variable costs that are having the biggest impact on profitability. You'll then drill down even further to determine what is causing variable costs to rise and come up with more specific recommendations.

Building a graphic representation (tree, decision diagram, etc.) of parameters, factors and other influencing elements will help you structure your thought process, keep from missing key aspects of the case, and make a strong argument for the recommendations you'll make.

Using a framework or structured approach to developing a recommendation for a case study interview question provides the added benefit of giving the interviewer something to take back and present to his or her superiors to make the case that you're the right person for the job.

Whatever you do, don't force-fit frameworks. If a particular framework doesn't apply to the case, don't use it. Most frameworks incorporate universal concepts that can be applied to various business issues. Use the concepts you've learned in school or through prior work experience to support your analysis of the case. Show your interviewer that you understand these business concepts well enough that you can apply them to the specifics fo the business issue being presented in the case.

Below we're going to present several case interview questions organized by question type. To perfect your ability to perform well in case interviews, we recommend reviewing each question and then developing a logical framework or approach for answering each one.

**Standard Case Interview Questions**

- What would be your approach for introducing a product into a foreign market? What are the risks and benefits to consider i.e. producing in your own country vs producing in the new country, etc?
- Company ABC is struggling, should it be restructured? Identify the three main problems it's facing. What is the most important problem the company is facing? How would you recommend the company address this problem? How would you turn this company around? Provide your reasoning for your recommendation(s).
- A toy company has been experiencing decline sales for the last two seasons. Research suggests that introducing several new product lines is the solution. Develop a marketing strategy for the company's largest product line, including pricing, product packing, etc.
- A large chain of retail clothing stores is struggling with profitability. Bases on your review fo the company's financial statements, what problems can you identify? Can this company be turned arounds? How would you go about deciding?
- A new Eddie Bauer Store is being opened up in London. Discuss all the marketing issues regarding the opening of this new location.

- Take in information quickly and remember what you hear.
- Identify key issues, prioritize and logically solve problems.
- Make quick, yet accurate, decisions.
- Manage time efficiently.
- Perform under pressure.
- Be aware of resource constraints.
- Identify customer needs.
- Be original and creative.

**Market Sizing Case Interview Questions**

- Please provide the total weight of a fully loaded Jumbo Jet at the time of take off.
- How many light bulbs are there in the United States?
- How many photocopies are taken in the United Kingdom each year?
- How much beer is consumed in the city of New York on Fridays?
- How many people sell AMWAY products in the United States?
- If there are 7,492 people participating in a tournament, how many games must be played to find a winner?
- How many golf balls will fit in the Empire State Building?
- How many car tire are sold in Canada each year?
- Given thhe numbers 5 and 2000, what is the minimum number of guesses required to find a specific number if the only hint you're given is "higher" and "lower" for each guess made?
- How do you determine the weight of a blue whale without using a scale?

- Take time to think before you answer the question.
- If given a pen and paper, take notes and write down key information. Use the paper to make calculations, write down ideas and structure your answer.
- Ask additional questions if you feel you are missing information. The interviewer is often expecting you to ask to find missing information.
- Use lateral thinking and be creative. There isn't always just one right answer. Just make sure your answer is backed up by sound logic and numbers that make sense.
- Make sure you know your math. At minimum you'll need to perform some basic arithmetic or mathematical calculations.
- These quesitons are often used to test your ability to structure, as well as your ability to think laterallly, make logical links and communicate clearly.
- Make mental calculations quickly by making sensible estimates and rounding numbers up or down.
- Does your answer make sense? If you're answer doesn't make sense, chances are you've made a bad assumpation, estimate or calculation. Go back and carefully check your work and provide a new answer.
- You can use business frameworks (SWOT, Porter's Five forces, etc.) or mind mapping to support your analysis and answers, as long as it makes sense.
- Many market sizing questions revolve around issues being faced by an organization or industry. Commercial awareness can be very important to answering market sizing questions.

**Logic Problems**

1. At 3:15, how many degrees there between the two hands of a clock? (J.P. Morgan interview question).

2. A fire fighter has to get to a burning building as quickly as he can. There are three paths that he can take. He can take his fire engine over a large hill (5 miles) at 10 miles per hour. He can take his fire engine through a windy road (7 miles) at 9 miles per hour. Or he can drive his fire engine along a dirt road which is 8 miles at 12 miles per hour. Which way should he choose?

3. You spend 21 dollars on vegetables at the store. You buy carrots, onions and celery. The celery cost half the cost of the onions. The onions cost have the cost of the carrots. How much did the onions cost?

4. You spend a third of all the money you have on a piano. Half of your remaining money you use to buy a piano chair. A quarter of the rest of your money you use to buy piano books. What porportion of you original money is remaining?

5. Why are manhole cover always round, instead of square?

6. In the Chicago subway system there are two escalators for going up but only one for going down to the subway. Why is that?

7. You find three boxes at the store. One contains onions. Another contains potatoes. The third contains both onions and potatoes. However, all three of the boxes are labeled incorrectly so it's impossible to tell which box contains what. By opening just one box (but without looking in) and removing either a potatoe or onion, how can you immediate label the contents of all the boxes?

8. There are 8 bags of wheat, 7 of which weigh the same amount. However, there is one that weighs less than the others. You are given a balance scale used for weighing. In less than three steps, figure out which bag weighs less than the rest.

9. There are 23 rugby teams playing in a tournament. What is the least number of games that must be played to find a tournament winner?

The following are the answers to the 9 logic problems above:

**Clock**

If you thought the answer was zero degrees, you'd be incorrect. At 3:15, the clock's minute hand will be pointing at 15 minutes, exactly 90 degrees clockwise from vertical. At 3:15, the clock's hour hand will exactly one quarter of the distance between 3 O'clock and 4 O'clock. Each of the 12 hours on the clock represents 30 degrees (360 degrees divided by the 12 hours on the clock). Consequently, one quarter of an hour is exactly 7.5 degrees, so at 3:15 the minute hand will be at 97.5 degrees. So there is a difference of

**7.5 degrees**between the hour hand and minute hand at 3:15.

**Fire Fighter**

Driving his fire engine 5 miles at 8 miles per hour takes 37.5 minutes. Driving his fire engine 7 miles at 9 miles per hour takes about 47 minutes. Driving his fire engine 8 milles at 12 miles per hour takes 40 minutes. So he should choose to drive his fire engine

**over the hill**.

**Store**

Answering this problem just requires some simple algebra. If we assume the cost of celery = x, then the cost of onions = 2x, and cost of the carrots is 4x, such that the total cost of all vegetables = x + 2x + 4x = 7x = 21 dollars. Consequently, x = 3 dollars. Hence, the onions cost 6 dollars.

**Piano**

You spend a third of all the money you have on a piano, so you're left with two thirds (2/3). You spend half (1/2) of the remaining two thirds on a piano chair, which leaves you with just one third of what you started with (1/2x2/3=1/3). You spend a quarter (1/4) of what you have remaining (1/3) on piano books, which leaves you with one twelth of the original (1/4x1/3=1/12).

**Manhole Cover**

A square manhole cover can be dropped down the hole if turned diagonally to the hole, where round covers can't be dropped down manholes.

**Chicago Subway**

People coming into the subway tend to arrive at different times, so the flow of people down the escalators is a more even stream. Conversely, when people get off the subway they typically all arrive at the escalators at about the same time. Consequently, two escalators are need to handle people leaving the subway, where only one is required for people arriving.

**Three Boxes**

Just open the box that is labeled "Onions and Potatoes". Since none of the boxes are labeled correctly, this box must contain only onions, or only poatatoes. If you remove a potatoe from this box, the box must be the "Potatoes Only" box.

One of the remaining two box has to be the "Onions Only" box. However, the only you currently have it labeled "Potatoes Only", and the other is label "Onions Only". So the box labled "Potatoes Only" must be the box that contains only onions, and the box labeld "Onlions Only" must be the box that has both potatoes and onions.

**Bags of Wheat**

Immediately, take any 2 of the bags and place them to the side. Weigh 3 of the remaining six bags against the other 3 bags. If these bags weigh the same, that means the bag that weighs less must be one of the two that you immediately placed to one side. If this is the case, weigh the 2 bags you placed to one side against each other to find out which one weighs less. You've now found in your bag.

However, upon weighing the sets of 3 bags against one another you find that one set weighs more than the other set, place one of the bags from the set of heavier bags aside and weigh the remaining two bags to find out which one is heavier. If they are of equal weight, the you know that the bag you place to one side is the bag you're looking for.

**Rugby Tournament**

In a tournament, every rugby team except the winner is eliminated from the tournament after being defeated just once. Hence, the number of games required to find a tournament winner is going to be one less than the number of teams, or 22 in this case.

**Business Case Interview Questions**

- How would you work with a subordinate who is underperforming?
- You're consulting with a large pharmacy with stores in multiple states. This company has improved sales but experienced a decrease in revenue. As a result, it is contemplating store closings. Explain how you'd advise this client?
- You are working directly with a company's management team. It is organizing a project designed to significantly increase revenue. If you were provided with data and asked to supervise the project, what steps would you take to ensure it's successful?
- You have been assigned to work with a small company that manufactures a popular product. However, a competitor begins selling a very similar product which incorporates state of the art technology. What would you advise your client to do?
- You have been assigned to advise a company with a large Western European market. Company management wants to open the Chinese market. What advice do you have for this company?
- The firm has assigned you to consult a company intending to drop a product or expand into new markets in order to increase revenue. What steps would you take to help this company achieve its objective?
- You have been assigned to consult a shoe retailer with stores throughout the nation. Since its revenue is dropping, the company has proposed to sell food at its stores. How would you advise this client?

**Case Interview Resources**

**Books**

*Vault Guide to the Case Interview**Vault Career Guide to Consulting**Case in Point: Complete Case Interview Preparation**Mastering the Case Interview**Ace Your Case! Consulting Interviews*(series 1-5)

**Interactive Online Resources**