🔍 Guesstimates: Making Informed Estimates 💭
The term "Guesstimates" is a fusion of two words: "Guess" and "Estimates." These questions challenge you to arrive at a specific number, often referred to as a "ballpark figure," with very limited information.
📝 Here's how to approach and crack them:
1. Top-Down Approach: Begin with the larger number and then break it down into smaller conditional chunks to reach the final figure.
🔢 Example: Estimate the annual number of toothbrushes sold in India?
Population of India ➡️ Regular/electric/natural toothbrush usage per person ➡️ Consumption frequency or number of toothbrushes used by a person in a year ➡️ Final estimate #
2. Bottom-Up Approach: Start with granular information and extrapolate to arrive at the number.
🔢 Example: Estimate the annual number of toothbrushes sold in India?
Number of toothbrushes used by a person in a year ➡️ Regular/electric/natural toothbrush options ➡️ Number of people in India with similar habits ➡️ Final estimate #
Both of these approaches work well for questions related to product consumption/usage/purchase.
3. Constraint-Based Approach: Identify supply-side constraints for the product or service and work through them to reach the final outcome.
🔢 Example: Estimate the total number of flights taking off from Delhi airport in a day?
Constraints: Limited number of terminals (maybe 2 or 3) ➡️ Time taken for a flight to take off (15-20 minutes) ➡️ Maximum four flights can take off in an hour ➡️ Divide day into peak and non-peak hours ➡️ Add the flight takeoffs in both peak and non-peak hours ➡️ Get the number.
This approach works well for questions with constraints.
4. Simple Maths Approach: For questions like "How many footballs can be crammed into the Boeing 747?" consider basic math calculations.
🔢 Example: Volume of the Boeing 747 / Volume of a football ➡️ Result.
Remember these key points:
🔹 Make logical assumptions to arrive at a final answer.
🔹 Round off numbers to simplify calculations.
🔹 Be structured and note down all assumptions and numbers.
🔹 Memorize a few useful statistics and formulas.
Guesstimates challenge your analytical skills, and combining multiple approaches may lead to the best estimate. So put on your thinking hat and start guesstimating! 💪🧠💡