Framework For Cracking Guesstimate Questions [+Tips & Examples]

0 min read

Ever wondered how many manhole covers there are in your city? Or how much pizza is consumed in your country annually? These seemingly impossible questions are the realm of guesstimates – estimation problems designed to test your analytical thinking and problem-solving skills. 

Guesstimate questions are estimation problems that require candidates to logically approximate a value using limited information. These questions are very commonly asked in job interviews, competitive exams, and business case competitions. They test an individual's problem-solving ability, logical reasoning, numerical skills, and structured thinking.

As the name suggests, rather than arriving at an exact answer, guesstimation focusses on breaking down the problem into manageable components and making reasonable assumptions. Sounds tricky? This article will equip you with the right framework and expert tips needed to crack these challenging questions. 

Solving Guesstimate Questions: An Easy & Structured Framework

There's a world of difference between guessing and guesstimating. If you just throw out a random number, that's a guess. It is arbitrary and likely far from reality. Guesstimating, on the other hand, is a structured approach to estimation. It is about making reasonable assumptions and using logical reasoning to arrive at a ballpark figure.

So, when faced with a seemingly impossible question like "How many burgers are eaten in Delhi in a single day?", don't panic! Guesstimating provides a framework to tackle such challenges. It transforms an intimidating guess into a reasoned estimate, grounded in educated approximations,rather than just pulling numbers out of a hat. 

But how do we actually do this? Here's how the framework works. 

Step 1: Understand the Guesstimate Question

"If I had an hour to solve a problem, I'd spend 55 minutes thinking about the problem and 5 minutes thinking about solutions." - Albert Einstein

This quote holds especially true when it comes to guesstimates. Hence, the first step in the process of solving a guesstimate question is conceptual thinking, wherein you are not quantifying or solving anything yet, but just recognizing what matters. Here's how you can start:

1. Carefully read and interpret the question. 
2. Identify what needs to be estimated and any key variables that can influence the answer.
3. Clarify any vague, confusing, or broad terms and think about constraints.

For example, if the question is 'Estimate the number of restaurants in Mumbai', clarify what qualifies as a restaurant, like, is it dine-in only, or is street food included?

For key variables, consider factors like population, income levels, food habits, nature of the city, etc. We know Mumbai is a diverse and populated city with a considerable number of upper-class (frequent diners) and middle-class people (occasional diners). It also has a massive base of working professionals, students, and migrants for whom eating out is a regular part of life.

All this sets you up to break the problem into manageable parts in the next step.

Step 2: Break Down the Problem

1. Convert your Step 1 understanding into concrete, small, manageable parts. So, you move from 'these factors matter' to 'here’s how I will use them.'
2.  Estimate the percentage/number of elements that influence the final estimate.

Example: For estimating the number of restaurants in Mumbai:

• Estimate Mumbai’s population.
• Approximate the percentage of people who dine out regularly.
• Assess the average number of people a restaurant serves per day.
• Calculate how many restaurants are required to meet that demand.

This modular approach makes complex problems easier to tackle logically.

Step 3: Make Assumptions and Use Approximations

1. Use real-world knowledge and logical estimates where exact data is unavailable.
2. Choose round figures (like 10 million, 50%, 100 meals per day) to keep calculations easy and the logic clear.

Example: Let's say Mumbai's population is 20 million, we can assume that half the people eat outside once a week at dine-in restraunts. Since Mumbai is a busy city, we can also assume that each restaurant serves 200 people daily.

Step 4: Perform Calculations Step-by-Step

1. Use simple arithmetic operations to calculate intermediate steps.
2. Work methodically, i.e., calculate intermediate values, ensure units are consistent, and revise assumptions if the numbers seem unrealistic.

Example: So, now we know that 10 million people eat outside once a week, which can be said as 10 million meals per week.

If each restaurant serves 200 meals per day, then over a week (7 days), each restaurant serves: 200 meals/day × 7 days/week = 1,400 meals per week.

Now, to calculate the total number of restaurants, we divide 10 million meals/week by 1,400 meals/restaurant/ week, which is 7,143 restaurants. This can be rounded off to 8000 restaurants. 

Step 5: Validate the Answer

1. Cross-check the answer with common sense and real-world references.
2. If possible, compare your estimate with known statistics.

Example: If government reports say Mumbai has 10,000 restaurants, an estimate of 8,000 is reasonable.

Remember: In guesstimation, the process is often more important than the precise answer. Your reasoning and assumptions are what count. While getting close to the actual figure is great, demonstrating a sound approach and logical breakdown of the problem is key. If your estimate falls within a reasonable range, means you've nailed it.

Solving Sample Guesstimate Questions 

Case 1: How many cups of tea are consumed in India per day?

Step 1: Define the Approach

We estimate tea consumption by considering the population, percentage of tea drinkers, and cups consumed per person.

Step 2: Estimate the Population and Tea Drinkers

• Total population of India ≈ 1.4 billion
• Assume 70% of Indians drink tea daily → 0.7 × 1.4 billion = 980 million tea drinkers
• Average cups per tea drinker = 2 cups per day

Step 3: Calculate Total Tea Consumption

Total cups of tea = 980 million × 2 = 1.96 billion cups per day

Case 2: How many mobile phones are sold in India per year?

Step 1: Define the Approach

We estimate the total sales by considering the population, phone replacement cycle, and new buyers.

Step 2: Estimate Mobile Phone Users

• Total population ≈ 1.4 billion
• Assume 60% own a phone → 0.6 × 1.4 billion = 840 million phone users
• Assume an average phone replacement cycle of 3 years
• New smartphone users per year = 50 million (considering first-time buyers and population growth)

Step 3: Calculate Total Phone Sales

• Phones replaced per year = 840 million / 3 = 280 million
• Total mobile phones sold annually = 280 million + 50 million = 330 million phones per year

Case 3: How many petrol stations (fuel pumps) are there in India?

Step 1: Define the Approach

Estimate based on vehicle demand and the fueling frequency per station.

Step 2: Estimate Vehicles and Fuel Demand

• Assume India has 300 million vehicles (including two-wheelers, cars, and commercial vehicles).
• Average refueling frequency: once per week
• Fuel stations operate 24/7, serving 500 vehicles per day

Step 3: Calculate Number of Fuel Stations

• Total refuels per day = 300 million / 7 ≈ 43 million refuels per day
• Number of fuel stations required = 43 million / 500 = 86,000 fuel stations

Practice makes perfect! Sharpen your guesstimate accumen with this course on Unstop. 

Expert Tips to Solve Guesstimate Questions! 

Here are some tips that will help you become a pro in guesstimating:

1. Restate the question: Before you jump in, clearly restate the question in your own words. This ensures you understand it correctly.

2. Identify the core: What is the fundamental quantity you're trying to estimate? Is it a number of objects, a total volume, a market size, etc.? This is your "pivot" point.

3. Ask clarifying questions (if allowed): If there's any ambiguity, politely ask clarifying questions. For instance, "Are we considering the entire metropolitan area or just the city center?" or "Are we talking about all types of X, or just Y?"

4. Choose a Framework:

• Population-based: If the question relates to people (e.g., number of users, market size), start with the relevant population (national, regional, or city).
• Area-based: If it relates to physical space (e.g., number of trees in a forest, number of gas stations in a city), start with the relevant area.
• Volume-based: If it relates to capacity or quantity (e.g., amount of water in a lake), start with the relevant volume.
• Process-based: If the question involves a flow or a process (e.g., number of pizzas sold in a day), break down the process into steps and estimate the quantities at each step. This is a good pivot for these kinds of questions.
• Unit-based: Sometimes, you might start with a single unit and then scale up. For example, "How much coffee does an average person drink in a day?" and then scale up to the population.

5. Make reasonable assumptions: For each variable, make a reasonable guess. Be transparent about your assumptions and explain your reasoning. It's okay to say "I don't know the exact number, but I'd estimate it to be around X because..."

6. Use round numbers: Don't get bogged down in precise calculations. Round numbers make the math easier and the focus should be on the estimation process, not exact arithmetic.

Mastered guesstimates? Now, unlock a tried-and-tested framework to win any case study challenge. Click here to read!

Conclusion

Guesstimate questions require structured thinking, logical assumptions, and step-by-step calculations. Practicing these problems enhances problem-solving skills, improves numerical estimation, and prepares candidates for real-world analytical challenges. Now that you're armed with these tips and techniques, it's time to put them to the test. The more you practice, the more confident and skilled you'll become. All the best! 

Frequently Asked Questions (FAQs)

Q1. How accurate should my guesstimate be?

Guesstimates don’t require precise answers but should be logically sound and within a reasonable range of the real-world value.

Q2. What are common topics for guesstimate questions?

Population-based estimates, market sizing, consumption-related questions, and logistics-related estimates.

Q3. How can I improve at solving guesstimates?

Practice regularly, familiarize yourself with real-world statistics, and develop a structured approach to problem-solving.

Q4. Can I use real-world statistics in my answer?

Yes, but ensure you state them as reasonable assumptions and be prepared to explain how they impact your estimate.

Q5. Are guesstimate questions only for consulting interviews?

No, they are also used in corporate competitions, business strategy roles, and exams testing analytical thinking.

Suggested Reads:

• Conquering Job Transition Anxiety
• Upskilling Along With A Full-Time Job? It's Possible!
• How To Understand Company Culture Through Reviews and Insights?
• Top 10 Best Ways To Evaluate A Company Before Accepting An Offer