An Example Question
To get you started on how to tackle a case study interview question, here is a very basic example of one candidate's analysis of a case study question:
Question: How many cars are in the USA?
Answer:
Is it ok if I think about the problem out loud? Here's how I would think about solving this problem:
1. We need to determine how many households there are in the U.S. I estimate that there are 120 million households in the U.S. Does that sound right?
2. Since the U.S. is a prosperous nation and many families now have several cars, I estimate there are 1.2 cars per household
3. Households which live in cities don't normally need cars, so I estimate that 20% of the households live in cities without cars.
4. Since cars do not live forever, I estimate that 2 million cars are turned into scrap metal each year
5. But families are not the only ones who own cars. Companies have corporate fleets for employees. Car rental companies have cars. The government has cars. I will estimate that companies in the US have 100,000 cars, car rental companies have 250,000 cars, and the various government agencies have another 500,000 cars.
6. Car manufacturers want to sell new cars, and they need to keep an inventory of cars. So let's assume that the number of new cars is equal to the number of car which are going to be retired this year. I am basically assuming the US car market is not growing. We said earlier that number is 2 million cars
7. So, my rough estimate is the US has about 117 million cars.
As you can see from that sample answer above, the actual answer is not what is important. Remembers, odds are the interviewer probably doesn't know the answer either.
But what is important is the sample answer demonstrated creativity. Thinking about customer segments, people in cities, companies, government agencies, and car dealers demonstrated the ability to think about the problem through many different lenses to the interviewer.
The other thing that is important is the order of magnitude of the assumptions. They certainly do not need to be accurate, but they should be directionally correct. For example, it doesn't matter if there are 100 million households in the US, but to say there were 5 households would obviously be foolish.
Read on for some practice questions.
STIMATION QUESTIONS
• How many gas stations are there in India in any given year?
• What is the worldwide market for digital cameras likely to be in 5 years?
• How many airplanes are in the air right now?
• How many golf balls are sold in China each year?
ACTUAL OR THEORETICAL CLIENT QUESTIONS
• A business wants to go create an online store. What is your advice?
• A package delivery company plans on offering a new service where customers can drop a package directly into a driver's vehicle. What issues need to be thought about?
BRAIN TEASER QUESTIONS
• Why are manhole covers round?
• How do you know if the light inside refrigerator is on or not?
