In Career, Education, Salary

How to answer a rather random business case interview question

I was chatting with Jessica the other day and she mentioned how she was blindsided with a really strange interview question that went like this:

How many golf balls are sold in Canada?

Sounds TOTALLY random right?

stock_golf-ball-play-leisure-exercise

Well it’s not.

It’s actually something that gung-ho business school-type interviewers use to screen candidates to test for logic, basic math skills and how fast you can think on the fly.

The way to answer it (as I was taught in school) is to keep these things in mind:

  • Keep the math simple
  • Use the (few) facts you have on hand
  • Talk out loud as you are reasoning through the problem

KEEP THE MATH SIMPLE

Use 10s or 100s. Don’t try and get fancy with 75 or any odd numbers that are hard to multiply, add or subtract. You need to keep this simple so that you don’t need a calculator under such pressure.

USE THE ACTUAL FACTS YOU HAVE ON HAND

You don’t need many, just one is enough.

For example, you know there are:


  • 10 provinces in Canada
  • 3 territories

We can safely assume that no one golfs in the Territories, so just concentrate on the provinces as your number.

TALK OUT LOUD AS YOU ARE REASONING THROUGH THE PROBLEM

Talk as you are writing down the calculations.

In the above example, you already know that there are 10 provinces in Canada, so now you can make up a few facts or logical assumptions.

Something like this:

  • There are golf courses in Canada (guess at this number, say 10 or something because there is on average ONE in each province)
  • There are people who golf abroad who also buy golf balls, let’s say 10,000 in each province on average.

Then you make up some guesstimate numbers:

GOLF COURSES THAT BUY GOLF BALLS:

10 golf courses could buy 500,000 golf balls each year on average

500,000 x 10 = 5,000,000 golf balls

PEOPLE WHO GOLF AND BUY GOLF BALLS:

10,000 people x 10 provinces = 100,000 people in total

100,000 people x 100 golf balls a year = 10,000,000 golf balls

TOTAL GOLF BALLS SOLD IN CANADA

Now add the two numbers together:

5,000,000 + 10,000,000 = 15,000,000 golf balls sold in Canada each year

And done.

That’s how you solve a case study interview question.


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Sherry of Save. Spend. Splurge.

I got out of $60,000 of debt in 18 months using TheBudgetingTool.com. Since then, I have worked 50% of my career (taking 1-2 year breaks), and quadrupled my income within 2 years of graduating, going from $65K to $260K (savings rate = 85%). I could retire today if I wanted, but love my work-life balance as a freelancing consultant in STEM (Science, Technology, Engineering, Math). I also post daily on Instagram @saverspender.

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19 Comments

  1. L
    Lila

    I feel questions like these are silly, pompous and pointless. Although you did a great job in explaining on how to solve it. 😀

    I would do my research on the company on glassdoor and probably avoid a company that asks these questions.

    These questions seem to be more normally common with IT fields and for someone who is interested in climbing the corporate ladder like a business executive.

    Google used to ask brainteasers and they learned and admitted recently that these weirdo questions have nothing to do with hiring the right person.

    http://www.pcmag.com/article2/0,2817,2420764,00.asp

    http://www.nytimes.com/2013/06/20/business/in-head-hunting-big-data-may-not-be-such-a-big-deal.html?pagewanted=all&_r=0

    “On the hiring side, we found that brainteasers are a complete waste of time,” Laszlo Bock, senior vice president of people operations at Google, told The New York Times. “How many golf balls can you fit into an airplane? How many gas stations in Manhattan? A complete waste of time. They don’t predict anything. They serve primarily to make the interviewer feel smart.”

    So if Google is no longer asking knockouts like “how many vacuums are made every year in the USA?” then what type of questions is it asking? According to Bock, the Web giant is relying on more behavior-based queries, like “Give me an example of a time when you solved an analytically difficult problem.”

    “When you ask somebody to speak to their own experience, and you drill into that, you get two kinds of information,” he explained. “One is you get to see how they actually interacted in a real-world situation, and the valuable ‘meta’ information you get about the candidate is a sense of what they consider to be difficult.”

    Meanwhile, Google also no longer asks all potential employees for a transcript, GPAs, and test scores — unless you’re just a few years out of school. The Web giant found that this information — like brainteasers — doesn’t serve as a predictor of who will prove to be a good employee.

    “One of the things we’ve seen from all our data crunching is that G.P.A.’s are worthless as a criteria for hiring, and test scores are worthless — no correlation at all except for brand-new college grads, where there’s a slight correlation,” Bock said.

    Reply
    1. save. spend. splurge.

      Almost every consulting firm asks these questions. I had to go through this when I did interviews..

      Honestly, interviewers should just feel whether or not that person would be a good fit (vibe-wise) and be done with it.

      Reply
      1. L
        Lila

        @save. spend. splurge.: Ah! It’s the consulting firms that ask that? Makes sense, I imagine the interviews for those are much more intense.

        Reply
        1. save. spend. splurge.

          Yes, mostly consulting firms ask those silly questions because you need to be able to create business case studies and come up with solutions or ideas based on facts.. *shrug*

          Reply
          1. L
            Lila

            @save. spend. splurge.: Okay I get where you are coming from. I imagine they want you to think on your toes, be willing to be flexible, and hit the ground running with whatever they throw at you.

            Maybe its their way of getting you to think “out of the box.”

            That makes sense. I got you. 😉

  2. Kassandra

    In my early twenties I had interviewed for a position and had a question similar to this along with a full on math, psych and french test. It was worse than school! But, they needed to narrow down the field of applicants from thousands to just the twenty that they selected to hire. I ended up being one of the twenty people they hired. As you said, keep it simple in terms of figures and communicate the rationale of how you came up with your response. It gives the interviewer a lot of insight on the person being interviewed.

    Reply
    1. save. spend. splurge.

      Whoa!.. Math and French test? Brutal.

      Getting your ideas and thought across in a simple manner can be difficult.

      Reply
  3. Stefanie @ The Broke and Beautiful Life

    I don’t like these kinds of questions, particularly in a stressful situation like a job interview.

    Reply
    1. L
      Lila

      @Stefanie @ The Broke and Beautiful Life: Totally agree with you. Maybe for those not in consulting, we should treat these type of questions as a lark and stay relaxed as we attempt to answer them.

      Reply
  4. t
    tomatoketchup

    How about just saying “I don’t know”?

    Reply
    1. save. spend. splurge.

      *LAUGH*

      You can’t say that if they’re asking you the question 🙂 They’re trying to test your basic math skills and logic / problem-solving skills.

      Reply
      1. t
        tomatoketchup

        @save. spend. splurge.:

        But I don’t see how the question has anything to do with math or logic. If you’re not in the golf industry, you probably will have no context to even begin to answer such a question.

        I would rather someone tell me “I don’t know” and do some proper research to get the correct answer than to just make guesses based on questionable assumptions. I’d be very curious to see what kind of answer the interviewer is really looking for.

        Reply
        1. save. spend. splurge.

          HAHAH! I know it sounds ridiculous but it’s problem solving with nothing to go on but a few facts and guesses. This is the great big secret of the consulting industry (GUESSING!) and business schools.

          I was legitimately schooled on how to answer these questions and this is what they expect you to say during an interview. They give you a question or a mini case study and you have to create a case with the few facts you have, run some numbers and give a quick assessment in 15 minutes with nothing else to go on, no research, etc.

          They just want to see that you’re smart enough to reason out how to arrive at the answer, such as knowing that you need to count how many golf courses there are, and then to figure out how many golf balls are used, take the number of members at each club and multiply by the average of balls golfers use in a day, multiplied by 365 to get the yearly amount, etc.

          The reason why they make you do it too, is because a lot of business information is not readily available either because the company is private, or public but doesn’t publish or reveal that info. To get that info, you might need to take a sales figure for instance, and guesstimate based on that sales figure and some rationalized logic, what that means in terms of how many widgets sold per year.

          The job has an investigative / guesstimate nature.

          As for saying “I don’t know”, that is an unacceptable answer. You will pretty much be guaranteed to NOT be called back for second round interviews because they’ll think you’ve given up without even trying… or you just can’t reason out how to quickly sketch a thought path / map towards getting the answer, even if all the numbers/figures are wrong, that stuff can be adjusted with further research if need be.

          The answer doesn’t need to be perfect / accurate / exact, it just needs to demonstrate that you can arrive at that answer with a set of questions you pose to yourself.

          Reply
  5. A
    AdinaJ

    I know this wasn’t the point, but … One course per province? Lol! There are, like, 15 just in and around Edmonton. I don’t know about the rest of the country, but there be some golf-mad people around here.

    Anyway, that’s a great answer. You’re interview-ready :)2/

    Reply
    1. save. spend. splurge.

      Best to pretend that you have no idea how many there are, unless of course you’re a freak about golf, then make it 10 courses per province.. but it just adds more zeroes unnecessarily.

      Reply
  6. NZ Muse

    Not really something I gotta worry about, but advice I always read is to focus on your reasoning and communicate your thinking – the actual answer isn’t necessarily important.

    Also – one golf course per province? That’s not rooted in reality is it? That’s just a nice easy number you picked as an example?

    Reply
    1. save. spend. splurge.

      Exactly, the actual answer is not important.

      And no, one golf course per province is not reality. It’s so you can find an easy number to work with even if it isn’t true.

      Reply
  7. Liquid

    I like the way you thought out the solution. I wouldn’t have thought about the number of balls purchased by golf courses. You must be pretty smart if you can keep track of all that math in your head, lol. One time when I was being interviewed I was asked what vegetable would I be if I had to choose one. I answered mushroom.

    Reply
    1. save. spend. splurge.

      Well if you use round numbers it’s easy…

      Why a mushroom? They are my favourite veggie…

      I think as a vegetable I’d have been a potato. I love potatoes.. very versatile.

      Reply

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