Case interview questions: putting your logic to the test
Posted October 13, 2011, by Josie Chun
What would you do if you went into an interview and were asked this question: how many meat pies were eaten in Sydney last week?
Some of us might be at a total loss if faced with such a question, but these ‘case interview’ questions are often used in interviews with management consultancies, investment banks and other sorts of organisations when recruiting for executive or strategic positions.
In a case interview, you are presented with a problem or asked to analyse a situation and you have to identify the key issues, address the problems involved and come up with a conclusion or recommendation.
The purpose of case interview questions is to see how you think – the logic and structure of your thought, your ability to quickly analyse and think through a complex problem, to prioritise and exercise common sense, and reach a sound conclusion with limited information within a short space of time. The interviewer also wants to see how you behave and communicate under pressure, whether you like problem solving and demonstrate creativity, flexibility and confidence. It’s not about your specific business knowledge or coming up with a ‘correct’ answer, even though there is often a quantitative component.
See an example of a case interview question and answer.
‘The key to these is not so much the actual answer, but the logic of how you go about arriving at the answer (without the use of any outside information – including Google!) and the clarity with which you arrive at certain assumptions about what is known versus what is unknown,’ says ex-management consultant Stephen Scheeler. ‘However, if your logic is strong, the answer is often pretty accurate as well.’
The key to dealing with case interviews is to stay focused and level-headed and break the question down into its component parts. If you manage this, you may just come out of the interview with flying colours – and maybe even a job offer.
How to prepare for case interview questions
If you’re heading into a case interview, it’s absolutely essential that you research and prepare. Use books and websites (for example, McKinsey, Boston Consulting Group and Harvard Business School have practice questions on their sites, and Marc Cosentino’s Case In Point is considered a great reference book), talk to people who have been through the process, read business magazines and periodicals, and attend a workshop if you can. The company you’re interviewing with may even have sample questions and advice for approaching such questions on their website.
It’s also important that you practise – the more the better. Practise not only going through the mental exercises, but also articulating your answers in a confident manner. Your ability to logically and persuasively talk through your thought processes is more important than the actual answer you come up with.
How to perform at a case interview
At the interview, listen carefully to the question and summarise it succinctly to make sure you’ve understood correctly and understand the objectives. Prioritise the issues and construct a logical framework for tackling the problem.
It’s important to begin by setting up a structure. Break down the variables, some of which you may have to calculate, and others which you’ll have to assume. Take well-organised notes and lay your notes out in front of you so you can see the whole case at a glance. For the maths, estimate and round numbers off for easy calculation. Write all numbers down.
It’s essential to ask questions and explain why you’re asking them. Asking questions will be expected of you and will give the interviewer insight into your thinking. These sorts of interviews are meant to be a two-way discussion, and your ability to ask pertinent questions is one of the things they’ll be looking for.
Stay focused and keep your eye on the key issues. Don’t go off on a tangent or get bogged down in minor details that aren’t crucial to the bigger problem.
Think out loud, because they want to follow your thought processes and logic. The interviewer may challenge some of your assumptions if they think you’re going down the wrong path, or even just to see how you handle being challenged as well as your ability to justify your approach or quickly correct it without getting defensive.
Watch for any other cues from the interviewer, which may be given to help you stay on track. If the interviewer brings up a good point that you haven’t thought about or points out an error in your logic, then acknowledge you were wrong and be able to change your answer. Whatever you do, try to be objective – because that is why consultants are hired.
Also let the interviewer know if you have considered something but dismissed it. Communicating your train of thought, including those considerations you reject, will demonstrate your thoroughness and breadth of thinking, and allow the interviewer to see how you exercise judgment.
Don’t be afraid to be creative and brainstorm. If you can think of an innovative approach to the problem, that will be sure to impress. Employers want creative, original thinkers as well as thoughtful and thorough ones – so try to be both.
Occasionally step back to take a look at the overall picture. Summarise where you’re at and what the implications seem to be.
Once you’ve come up with an answer, give a good summary that takes about a minute and explain how you have come to your conclusion. If appropriate to the question, provide practical recommendations that can be acted upon.
Project confidence. Instead of acting like you’re scared or getting flustered, be enthusiastic about taking on the challenge and regard such problem-solving as fun – this will show the interviewer you have the right attitude and will be both happy and good at your job.
Finally, don’t forget that as nerve-racking as case interviews can be, this is an important exercise and you will gain important information about the company you’re interviewing with by going through this process.
How to approach the meat pie question
So how many meat pies were eaten in Sydney last week? To answer this question, you could start with the population of Sydney, then estimate the number of people who eat meat pies. After that, consider how many they would eat in a day and the 7 days per week, and come up with a final answer. You could further refine your answer by breaking it down into different types of people: kids, adults, the elderly, men and women.
This is only a very simple example. Other more complex questions might be:
How many phone books are there in Sydney?
Estimate the market for lightbulbs in Australia.
What’s the worldwide annual production of ping pong balls?