Mastering the most common case interview questions is the first step towards acing your case interview and landing a coveted job offer. Crafting an impeccable resume and preparing for the fit interview are important, but just the beginning – the real challenge lies in conquering the case interview. To effectively prepare, you must understand the most common case interview questions. In this guide, we break down the 5 most popular case interview questions and how to successfully answer each one.
The 5 Most Common Case Interview Questions
How would you structure this business problem? What factors would you consider?
The most ubiquitous of the common case interview questions, “How would you structure this problem” is almost guaranteed to pop up in every interview! Why? Because structured thinking and communication are key consulting skills.
Your task is to transform a broad business problem into a framework consisting of 3 or 4 concrete sections that acts as a work plan for how you will solve the problem. This question typically appears at the beginning of the interview. You should take some time (around 2 minutes) to construct a framework before explaining it to the interviewer. Start by giving an overview of your plan before explaining each segment so the interviewer can easily follow along.
How big is this market?
Ah, market sizing! The quintessential consulting case interview question. Market sizing questions are common at the undergraduate level across firms and different case interview types. Read about the 6 different types of case interviews here.
You can approach market sizing questions with a “top down” (starting with the US population, for example, and working down) or a “bottom up” approach. The goal of this question isn’t to see if you can arrive at the “correct” answer – often, the interviewer will not even know the market’s exact size! Rather, the goal is for the interviewer to see if you follow a logical problem-solving process and can communicate that process clearly.
Solving a market sizing problem relies on crafting logical assumptions and using a well-segmented approach. Like with structuring questions, clear communication and thorough explanation are the most important elements to success.
Given the previous information, what will our profit margin be in 2025?
Math questions are among the most common case interview questions you will encounter. You can expect questions ranging from rough estimation to precise arithmetic and financial valuation. Effective communication is paramount. Especially in a virtual interview format – standard for many firms these days – overexplaining your math process is vital to ensuring that your interviewer can follow along. Read about our 7 tips for virtual interviews here.
First, recap the problem so you are sure you know what you are solving for and have captured all the key data. Then, plan to set up your math problem verbally and walk your interviewer through the steps you intend to take before conducting the calculations. By doing so, you give your interviewer a chance to correct your approach, if necessary, before you dive into the numbers.
Finally, don’t just stop once you have your solution. Sanity check (“Does this number make sense? Is it plausible?”) and then drive towards insights. By saying “the answer is X, which means that we should investigate Y and consider Z,” you can separate yourself from the pack.
Can you think of ways to bring down the costs associated with this project?
Brainstorming questions are common in case interviews. Often, an interviewer will ask a question that encourages you to think creatively and develop a list of possible options or solutions. A great approach is to structure your brainstorming the same way you might structure a case initially, albeit on the fly. By breaking down your approach (“I want to break down my suggestions into fixed and variable cost options,” for example), you buy yourself time and come across as organized and coherent.
The CEO just walked in. What would you recommend?
Most cases end with a recommendation. The question can take two forms: either a general “What is your recommendation?” or something along the lines of “The CEO knocked on your door and wants your thoughts. What do you say?” In the first instance, it’s appropriate to take some time to gather your thoughts before responding. In the second, you are expected to synthesize and respond on the fly.
To succeed, do the following. State a decisive recommendation and support it with facts from the case – you can provide 1-2 sentences of synopsis after stating your recommendation, synthesizing the case without repeating all of it. Finally, end by offering risks and next steps. Think like a consultant here – by listing risks, you are minimizing blowback if your recommendation doesn’t pan out as planned, and by offering next steps, you are selling more business for your firm!
Now that you understand the most common case interview questions, we’ll jump into 5 common questions about case interviews
5 Common Questions ABOUT Case Interviews
Why do consulting firms use case interviews?
Case interviews are an efficient way to see if strong candidates would make effective consultants. Think about it – the best way to see if a candidate would succeed in a role would be to have them perform that role for several months. Without that option, firms take the next best approach – an interview that directly mirrors the job. By evaluating your structuring, quantitative, creative, and communication abilities, interviewers can get a sense of whether you would make an effective consultant.
Will my entire interview process be case interviews?
Another common question about case interviews is whether case interviews make up the entirety of the interview process. The answer? It depends on the firm. At certain firms, the interview process consists mainly of case interviews except for a personal question or two at the beginning of the interview. At others, like McKinsey, a personal fit interview is weighted equally with a case. Regardless, you should be prepared for both fit interviews and cases. Need help? Work with 1:1 with an MBB coach to prepare.
How are 1st and 2nd round interviews different?
First round interviews are often shorter than their second round counterparts. Some firms structure their interview rounds so that the first round is a behavioral interview, and the second round is a case, or vice versa. If a firm uses multiple rounds of case interviews, the cases are often more complex in the second round.
One main difference, consistent across MBB, is that the first round of interviews will be with a consultant and the second with a partner. Expect more thorough discussion and pushback and a larger focus on rapport in the second round.
Can I bring a calculator?
Nope. Interviewers want to see that you can perform calculations by hand, so structuring your calculations and keeping your writing neat and tidy are extra important. Work with an MBB coach or complete our Mental Math for Consulting course!
If I slip up on the math, am I doomed?
Often, no. While major math issues are a problem, a minor slip up or two on the quantitative side of things is often not enough to derail your candidacy. Still, it’s important to take detailed notes and over-explain your process to stay on the right track.
Basics on How to Prepare for a Case Interview
Now that you have a great sense of how case interviews work, you’re on the right track to start preparing! Case interview prep is straightforward, and, with enough practice, anyone can master it, but it does take some time. Start practicing early, ideally 2-3 months before your interview.
What are the best ways to case prep? Live interviews and drills. Practicing live is the best way to hone your casing skills since case interviews require you talk, think, and write at the same time.
Start by completing 10-20 Market Sizing cases, ideally with a partner. Then, go through 5-10 cases with a friend. After that, feedback from an expert interviewer is the best way to get yourself over the finish line. An expert coach can quickly identify your specific gap areas and craft a plan to address them. Book time with a former MBB interviewer here.
Component-specific drills are another great way to set yourself up for success and brush up on your weaknesses. For example, check out our math drills.
Now that you have a better grasp of how case interviews work, the real work begins – preparing yourself for the interview! Remember that the majority of cases include some combination of the 5 most common interview questions and test your ability to structure, market size, think quantitatively, brainstorm, and synthesize information into a cohesive recommendation. Also, don’t forget that each question is a test of your ability to communicate, so prioritize explaining everything clearly.
Plan to set aside a good amount of time for consulting interview prep and focus on live case practice and structuring drills. The best approach? Work with us through our Black Belt case interview prep program. You’ll work 1:1 with an MBB coach to fine-tune your case interview skills, crack the code, and land your dream consulting offer!
- Free Case Interview Prep Course
- Case Interview: Complete Prep Guide
- Case Interview Frameworks: Ultimate Guide
- Case Study Samples: Video Examples With Answers