## Design an evacuation plan for this office building.

As with any complex on-the-job challenge, the first step to answering a question like this is to clearly identify the problem. If designing an evacuation plan was really your task on the job, you definitely wouldn’t be able to solve it in an hour-long meeting—you’d need a lot more information. So, when an employer asks … Read more Design an evacuation plan for this office building.

## Estimate the demand for plastic bags in the US.

The trick with this question is that typical population analysis isn’t enough. You must take into account residential use of plastic bags, as well as that of businesses, government employees, and so on, until you can muster some convoluted quantity to appease your interviewer. Also consider bans on plastic bags, as found in cities like … Read more Estimate the demand for plastic bags in the US.

## How many potatoes (in kg) does McDonald’s sell in a year in the UK?

Like most of these questions, it’s less about how much you know about McDonald’s or potatoes, but rather how you approach the problem. Start by estimating the number of restaurants in the region. As for potatoes per restaurant, you could estimate the number of orders of fries or hash browns every day, and the number … Read more How many potatoes (in kg) does McDonald’s sell in a year in the UK?

## How much does the Starbucks in Times Square bring in, in annual revenue?

Even for an insanely busy Starbucks, you can get pretty far by estimating the average ticket cost and the average traffic per hour, multiplied by 24, multiplied by 365. As always with market sizing questions, justify your assumptions, and use round numbers so you can get an estimate quickly and without errors. It turns out … Read more How much does the Starbucks in Times Square bring in, in annual revenue?

## What is the size of the market for disposable diapers in China?

Here’s a good example of a market sizing. How many people live in China? A billion. Because the population of China is young, a full 600 million of those inhabitants might be of child-bearing age. Half are women, so there are about 300 million Chinese women of childbearing age. Now, the average family size in … Read more What is the size of the market for disposable diapers in China?

## “What do you think” questions: These questions can range from: “How heavy is a car?” to “how long would it take to evacuate London?”

As a general rule, it’s best to break down the case into its smaller components. To use the car example: Think of all the components of a car, e.g. steel exterior, windows, wheels, engine, interior as well as variable weights (number of passengers, fuel, luggage). Assign weights to each of them, making sure that you … Read more “What do you think” questions: These questions can range from: “How heavy is a car?” to “how long would it take to evacuate London?”

## Individual-Based: How many novels are sold in the UK each year?

Looking at the UK’s population of 60 Million, and estimating average life expectancy in this country at 80 years, we can now calculate how many people there are in each age band. Realistically, there are fewer old people than young people, but to keep things simple we’ll just assume that there are 750,000 people in … Read more Individual-Based: How many novels are sold in the UK each year?

## Household-Based: How many toasters were sold in the UK last year?

Best way of answering: One household has about one toaster. The average British household consists of 3 people. Given that the UK population is 60 M there are 20,M households. Assuming a toaster needs to be replaced every 4 years, one quarter of all households are going to buy a toaster every year, i.e. 5,M … Read more Household-Based: How many toasters were sold in the UK last year?

## Population-Based: How many post offices are there in the UK?

Best way of answering: I live in a town of 12,000 people, we’ve got 3 post offices. Taking this as the average, I’ll assume that one post office serves about 4,000 people. The UK population is 60,000,000, so there are 15,000 post offices in the UK.

## How would you estimate the weight of the Chrysler building?

This is a process guesstimate – the interviewer wants to know if you know what questions to ask. First, you would find out the dimensions of the building (height, weight, depth). This will allow you to determine the volume of the building. Does it taper at the top? (Yes.) Then, you need to estimate the … Read more How would you estimate the weight of the Chrysler building?