Table Tennis ball case

Case Type: estimate or guesstimate.
Consulting Firm: Monitor Group first round job interview.
Industry Coverage: sports, leisure & recreation; transportation.

Case Interview Question #00507: How many ping-pong balls can fit into a Boeing 747 passenger airplane?

Possible Approach:

The best approach for an estimation or guesstimate case question is to think of a funnel. You begin by thinking broadly, then slowly drill down towards the answer. Let’s look at the approach in context. Referring to this particular case question, you know that you are looking for how many ping-pong balls fit in a 747 airplane. The first thing you need to determine is the volume of the ping-pong ball.

For any guesstimate/estimation case question you will need to understand whether your interviewer will be providing any direction or whether you will have to make assumptions. Therefore, begin your analysis of a guesstimate or estimation case question with a question to your interviewer, such as “What is the volume of a single ping pong ball?” If the interviewer does not know or refuses to provide any answer, then you will know that you must figure out the answer first. If the interviewer does provide the information, then your approach will be a series of questions. For this example, let’s assume your interviewer wants you to make the assumptions. Your verbal dialogue might go something like the following.