Article from The Muse. Written by Alex Cavoulacos. 

The case interview is a format in which you, the interviewee, are given a business problem (“How can BigCoal Co. double its growth?”) or a brain teaser (“How many tennis balls fit in a 747?”) to solve. Cases have gotten quite the reputation for being intense, quant-heavy, and just downright scary. But they don’t have to be—not the scary part, at least

We spoke with recruiters at top consulting firms to learn what really makes an interviewee “ace the case.” And while case interviews were once exclusively the domain of aspiring consultants, they’re now popping up everywhere from tech companies to NGOs. So, no matter where you interview, use these tips to sail on through.

1. Ask Questions—From the Start

In the beginning, you’ll typically be given important information about your case. Listen to it and take notes. And when the interviewer asks if you have any questions before proceeding—the answer is “yes”

First, summarize the situation and problem at hand, and ask clarifying questions if something was unclear (e.g., if there was a word you didn’t understand). This will not only highlight your listening skills, it’ll let you double-check that you understand the case that you’re about to start solving.

Then, do one better: Ask a “step back” question. A step back question is one the puts the case into context, and gets at the bigger picture beyond the information you were given upfront. For instance, if you’re given a case about a private equity firm that’s deciding whether or not to acquire a given company, a step back question could be: “Is this private equity firm also looking at other acquisitions in the industry and therefore evaluating this target versus others?” Most people don’t do this—so if you do, it’ll help you stand out as thoughtful and genuinely interested in the problem rather than just focused on getting through the interview

2. Engage Your Interviewer

Asking questions is also a great way to build a rapport with your interviewer from the start. Think of the case not as a test, but as a conversation through which you need to solve a problem. With this mindset, ask your interviewer for more information when you need it, explain your assumptions as you go, and talk him or her through your approach. All of these things will lead to a productive conversation, and you’ll likely find your interviewer quite helpful, especially if you get stuck.

Sometimes he or she may steer you in a different direction or suggest you think of things in a different way—and you should pay attention to such subtle cues and guidance. The more you bring your interviewer along in your thinking, the more he or she will enjoy working through the case with you, and the more opportunity you give him or her to help you solve the problem you’ve been presented with

3. Structure, Structure, Structure

A good structure is really the key to doing well with a case. It’s more important than your answer and it’s more important than the knowledge you bring in—it’s your chance to show “how you think.” The interviewer wants to know that you can take a bunch of information thrown at you and create a logical structure, process it, and get to a good answer (not “the” answer, mind you—with cases, there aren’t single right answers).

So, when asked to solve the problem at hand, first ask for a moment to think through it and collect your thoughts. Then, grab your pen and paper and get to work. Your goal, in the next 30 seconds or so, is to outline a logical structure that will help you work through the major issues of the case

A good structure breaks down the problem into components. For example, if you’re asked about profits, then you can split that into two components: “increasing revenue” or “decreasing costs.” Then, you can split each of those further—increasing revenue means “increasing your price” or “increasing the number of things you sell;” decreasing costs means “decreasing fixed costs” or “decreasing variable costs.” On the other hand, if you were asked about growth, you could break you answer into “selling more of what we have today” and “selling new products” or “selling in our existing markets” and “moving into new markets.”

Write down your structure, then explain it to your interviewer. And only then should you dive in to how, specifically, you would up the selling price, decrease manufacturing costs, or move into Asia. The bonus of this approach: If you go down one path and get stuck, you have an outline to fall back on.

4. Recognize Case Archetypes

Now, here’s a secret: There are really only a handful of case “types” that you will be given. They include entering a new market, developing a new product, growth strategies, pricing strategies, starting a new business, increasing profitability (or increasing sales or reducing costs), and acquiring a company. Turning around a company and coming up with a response to a competitor’s actions are also possibilities, but they’re asked much less frequently.

So, plan ahead and come up with clear structures in mind for each “type.” There is no right structure, and you should, of course, adapt your structure to be relevant to the case at hand. However, thinking through structures ahead of time will help you make sure you stay focused on the key issues during the case, even if unfamiliar jargon is thrown your way. Plus, structures give you a framework for organizing and talking through your information, and a safety net to fall back on if you get stuck.

As you practice cases, you should test out and refine your structures. See if they help you cover the important information and lead you down the path to solving the problem—and if not, revise them accordingly.

5. Practice Your Numbers

Many people freeze up on the quant section. And the best advice here is: The more you practice, the easier it will get. Here are a few pointers:

• Write out your formulas and thought processes as you’re doing your math. This will help you see if you need to ask for additional information to answer the question. Also, if you hit a wall, the interviewer will be able to help get you back on track more easily if he or she is aware of what you’re trying to do.
• Play and practice with numbers. If you trip up on zeros, try dividing and multiplying in scientific notation. Practice taking 10%, 20%, 25% of a number (moving the decimal over for 10% and halving it for 5% usually works well). Have an idea of what 1/5, 1/6, 1/7, 1/8, 1/9, and 1/10 are in percentage terms.
• When given a quant question, again, ask for a moment to gather your thoughts and structure the approach. Never feel pressured to respond right away.

6. Keep Up With Industries

You never know what industry the case you’re given will focus on. However, the more relevant you can make your questions and answers to the industry, the better.

Two things can help here. First, as you practice, keep a running tab of specific attributes particular to an industry (e.g., for airlines: the market is competitive on pricing, economics of coach vs. business travel are very different, capacity utilization is important, unions and fuel can be big drivers of cost). Second, keep current with the news. Reading The Economist every week is a great way to keep abreast of major trends in different industries and countries.

7. Practice—and Grab a Buddy

Read through cases yourself, do cases with your friends, and try out the cases on a company’s website. Often, business schools will compile case books and circulate them as well. Case in Point by Marc P. Cosentino is a good place to start. The more you practice, the more variants you will see, and the more comfortable you will be on the day of your actual interview.

Also, there’s no substitute for talking through cases out loud. Reading cases on your own, or doing them online, can be great for helping you practice your structures and your math, but there’s nothing like having to articulate your thought process in real time. Do yourself a favor by simulating the interview environment beforehand—grab a friend and give each other cases. You’ll also be surprised by what you can learn from sitting on the other side of the table

And finally—have fun. Yes, doing your fourth practice case in a row can be a drag. However, you should also get a sense during your practice if you really like problem solving through a case. If you enjoy your consulting interview, chances are higher you will enjoy the actual consulting work as well.