Interviews are a very important part of our professional lives. We all have to face it every now and then, whether you are a fresher, or an experienced job seeker. During such interviews, we face lots of similar or new categories of questions. Few are those we have practiced for thousand times and few show up to us out of blue. It doesn’t matter what is thrown at us as a question, we need to be ready to give our best shot. Guesstimates are those questions that are asked quite often and need good practice to solve.
Before reaching any solution, it is very important to understand what are these Guesstimates?
In very simple words, guesstimate* is a question where one has to derive an answer to them using valid guesswork or conjecture. We need to remember that the interviewer is not looking for an exact correct answer to arrive at. He/she is only interested in the approach that is taken by the interviewee to solve that problem. This is done to assess the problem-solving capabilities of the interviewee.
*https://en.wikipedia.org/wiki/Guesstimate
Guesstimates are often asked these days in different interviews of consulting, analytics, product based interviews, and now in B-Schools as well. There is no single way to solve such questions, it all depends upon the practice and guesswork, as the name suggests. But still, there are few ways we can make an approach to such questions.
Steps to follow to solve Guesstimates (let’s take an example simultaneously):
How many patients are getting admitted to medical facilities in India?
Be clear about the Question: Before you start applying your brain looking for a solution, think about the question for a few minutes and clarify it for yourself, even if you need to ask and re-ask the interviewer. Get all your doubts regarding the question sorted.
For this guesstimate, things to clarify:
What is the timeframe that we are considering?
Does “Patients” include only people who got admitted in the hospital for some longer period of time or can it also include people who came to the hospital to get some tests done?
The location where they got admitted is not clear. Are the hospitals as well as small clinics?
Are we considering the COVID-19 pandemic situation while answering this question?
Clarified answers:
How many patients are getting admitted yearly in India?
“Patients” include only the people who got admitted in the hospital for some operations.
Location includes only the hospitals which have the provision of getting patients admitted for any operation
We are not considering the COVID-19 pandemic situation. This calculation is for pre-COVID times.
Now we have some clarity.
Finalize the approach: Applying your logic to the question doesn’t mean looking for the solution, guesstimates are not very structured questions. We need to structure it first so that few things seem clear to us and then we can apply a few of our common logic to it. There are various approaches like top-down, bottom-up, process mapping, layout centric, or critical comparison, that can be used to solve the guesstimate. You can think about all of these approaches and then decide to go with one whichever seems the most appropriate one.
For this guesstimate, there can be many approaches, two of these can be:
- Based on the population statistics, keep on narrowing it down to the answer.
- Take the approach to decide the number of hospitals and clinics, their in-patients and out-patients ratio and then derive the answer
Let’s go with the first one.
Conclude: Now you have the question and the appropriate approach, but the trick is still there to use when you conclude your answer. If you have applied everything right, then the question will fall into the right palace you want it to. But it won’t be easy at all. You have to go through lots of brainstorming in that process.
So, let’s do some brain exercise for this guesstimate.
The population of India: 1,300,000,000 (take the approximate number so that it becomes easy to calculate)
Rural/Urban Ratio: 70/30
Rural Population: 70% of 1,300,000,000 = 91,000,000 (Let’s take it: 90,000,000)
Urban Population: 30% of 1,300,000,000 = 39,000,000 (Let’s take it: 40,000,000)
Guess some numbers but with some logic:
More people fall sick in urban areas than in rural areas, let’s take that number as if 10% of people fall sick in urban areas, 8% fall sick in rural areas. There are some studies that have shown these numbers. That’s why reading a lot helps. But if you don’t know these numbers, just guess some numbers. The logic is the most important thing here.
Rural population falling sick: 8% of 90,000,000 = 7,200,000
Urban population falling sick: 10% of 40,000,000 = 4,000,000
Now how many of these need admission to the hospitals. Let’s take a percentage of 20% as a constant for both rural and urban populations, as the level of seriousness of the sickness while assuming 8% and 10% for rural and urban respectively is the same.
Rural Population needing admission to hospitals: 20% of 7,200,000 = 1,440,000
Urban Population needing admission to hospitals: 20% of 4,000,000 = 800,000
Total no of people getting admitted to hospital in a year: 1,440,000 + 800,000 = 2,240,000
This was a good brain exercise. Wasn’t it? This is just one approach used in solving this guesstimate. You can try different approaches. Please remember to have a valid consideration while guessing the number. It is okay if you don’t know the correct number, but the logic you use to guess it is the thing to focus upon. Also, it is good to be prepared with few statistics* before you go for an interview.
*https://soumyagupta.in/useful-numbers-and-formulae-for-guesstimates-market-sizing-266cef59eb7d
And keep practicing. All the best!
