Ask a friend or classmate to make up a case on any topic that's relevant today. You can prepare for the interview by having a dialogue that takes you closer to solving the case step by step.

The actual topic doesn't matter. No one expects you to know the size of the market for contact lenses in Southeast Asia.

We want to see how you approach the case. Do you have a feel for what the ballpark figures might be? To prepare for estimating market sizes, you should make yourself familiar with some basic data, like population sizes. Rely on your common sense and make realistic assumptions.

Work out a structure. This will point the way to the solution. If you do lose your train of thought, your structure will help you find it again. Your interviewers will also help you. They don't want to trip you up – they want to support you and understand how you reached your solution.

That's why it's important to listen to any hints the interviewers give you. No one knows it all. Finding a good solution requires interaction with others. We want to see how you deal with the challenge. Concentrate on what really matters and show your interviewers that you can distinguish between important facts and irrelevant information.

Don't forget in your nervousness to listen carefully to how the case is formulated and what the interviewers say while you're working on it. Maybe they'll give you some hints. You can make a note of the key data. Successful consultants have a good plan, but they can also see when something is not working or it's time to change direction.

If you're unsure of something, just ask. We don't expect you to know everything right away. Also, we often leave out some details just to see how you deal with missing information. We'd rather hear a good question than a poor answer.

Communication is the key to success. Share your thoughts with us. Then we'll be able to see your thinking.