Management Consulting Estimation Questions

If there is no correct answer to any management consulting estimation question, why is it being used during case interviews by large consulting firms like Bain, Monitor and Booz? Read this post and understand the value of this type of question.

When an interviewer asks you the questions below, you will probably be surprised.

1. How many laptop computers are bought at a mall in a year?
2. How many hamburgers were ordered in the USA last month?
3. How long will it take you to move your house to another city?

That surprised initial reaction is normal. The sentences above sound so silly you’d wonder if they are serious case interview questions. Unexpectedly, they are. These estimation questions measure how logical you can be, how you break complex ideas into simple ones and how good you are at calculation. To elaborate this rationale, let’s try to answer the first question.

Be Logical

Come up with a method that will let you arrive at an acceptable answer. You just can’t tell the interviewer you need to go to all computer shops at a mall, look at their sales report for the last year and add the total number of purchased laptops. Of course, that is the most logical thing to do to get an accurate answer, but in a management consulting interview, the answer must be a specific number. This answer can only be generated once you have a sensible approach.

Draw a Structure

Since you’re already familiar with the method, it’s time to get into specifics. The details will give you the equation on how to get the satisfactory answer. In the interview, you must verbalize the steps in your mind so the interviewer will be able to gauge how analytic and creative you are.

To guesstimate the number of laptop computers bought at a mall last year, you can use the steps below. The steps were created with an assumption that each computer shop sells different brands of computers.

Step A

Estimate the number of ABC laptops bought in a day. If you say five, support your answer with a seemingly valid reason. You can mention the price, quality and other criteria customers use when they purchase a laptop, etc.

Step B

Multiply A with the possible number of brands a computer shop sells. If you say 10, mention the brand names you know – like Apple, Lenovo, Sony etc.

Step C

Multiply Step B’s product with the number of computer shops in a mall. (Name all the computer shops at a mall in your city. Let’s assume, six.)

Step D

Multiply Step C’s product with 365 days. (Or you can multiply it with the number of days in a week X number of weeks in a month X number of months in a year.)

Step E

Provide the answer. Based on our assumptions, the estimated answer is 109,500.

Use Mental Math

From the word estimation, it implies you will be using your mental math skills in answering this type of question. The interviewer might allow you to use paper and pen for calculation, but she or he would be more impressed if you can compute numbers mentally. So before the case interview, master the fundamentals of mental math.

Because you already understand the nature of estimation questions, try to read our explanation for brainteasers as another type of interview question. If you need more information on how to land a management consulting position, download our helpful consulting career guide here. It contains facts on the complete recruitment process most consulting firms follow.