"Equation = (# of phones sold in Africa every month * % pixel market share)
Africa population = 1.5 billion
Smartphone penetration = assume 50%
Assume smartphone penetrations grows 1% per year
Assume 2 year smartphone renewal cycle
Current smartphone population = 1.5B x 50% = 750M
Each year 50% of this populations gets a new phone = 375M
375M / 12 = ~31M per month
New smartphone population each year = 1.5B x 1% = 15M
15M / 12 = ~1 per month
31M + 1M = 32M smartphones sold per month
US mar"
Greg W. - "Equation = (# of phones sold in Africa every month * % pixel market share)
Africa population = 1.5 billion
Smartphone penetration = assume 50%
Assume smartphone penetrations grows 1% per year
Assume 2 year smartphone renewal cycle
Current smartphone population = 1.5B x 50% = 750M
Each year 50% of this populations gets a new phone = 375M
375M / 12 = ~31M per month
New smartphone population each year = 1.5B x 1% = 15M
15M / 12 = ~1 per month
31M + 1M = 32M smartphones sold per month
US mar"See full answer
"This is a Fermi problem — an estimation or approximation problem with limited information and back-of-the-envelope calculations. There's no right answer: interviewers want to understand how you think and how well you can explain your reasoning, rather than what you already know.
Recall the formula for Fermi problems:
Ask clarifying questions
Catalog what you know
Make equation(s)
Think about edge cases to add to equation
**Breakdown components of your equat"
Exponent - "This is a Fermi problem — an estimation or approximation problem with limited information and back-of-the-envelope calculations. There's no right answer: interviewers want to understand how you think and how well you can explain your reasoning, rather than what you already know.
Recall the formula for Fermi problems:
Ask clarifying questions
Catalog what you know
Make equation(s)
Think about edge cases to add to equation
**Breakdown components of your equat"See full answer
"Are we also considaring the office buildings or only houses? Both
So we know the NYC land area is 1254 sqkm
1 square kilometer = 247.105 acres that means 1254 sqkm will be = 309870 acr ( rounding)
So this is total space, in this say living area is 80% that means 80% * 309870 = 247896 acrs
In this 60% residential which will be 148738 acrs residential area and rest is 99158 acres are business blocks
Menas (148738/247) =602 sq km =602178 sq mtr residential and 401449 sq mtr for busine"
Indranil G. - "Are we also considaring the office buildings or only houses? Both
So we know the NYC land area is 1254 sqkm
1 square kilometer = 247.105 acres that means 1254 sqkm will be = 309870 acr ( rounding)
So this is total space, in this say living area is 80% that means 80% * 309870 = 247896 acrs
In this 60% residential which will be 148738 acrs residential area and rest is 99158 acres are business blocks
Menas (148738/247) =602 sq km =602178 sq mtr residential and 401449 sq mtr for busine"See full answer
Estimation
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"This is a Fermi problem — an estimation or approximation problem with limited information and back-of-the-envelope calculations. There's no right answer: interviewers want to understand how you think and how well you can explain your reasoning, rather than what you already know.
Recall the formula for Fermi problems:
Ask clarifying questions
Catalog what you know
Make equation(s)
Think about edge cases to add to equation
**Breakdown components of your equat"
Exponent - "This is a Fermi problem — an estimation or approximation problem with limited information and back-of-the-envelope calculations. There's no right answer: interviewers want to understand how you think and how well you can explain your reasoning, rather than what you already know.
Recall the formula for Fermi problems:
Ask clarifying questions
Catalog what you know
Make equation(s)
Think about edge cases to add to equation
**Breakdown components of your equat"See full answer
"This is another Fermi problem — an estimation or approximation problem with limited information and back-of-the-envelope calculations. There's no right answer: interviewers want to understand how you think and how well you can explain your reasoning, rather than what you already know.
Recall the formula for Fermi problems:
Ask clarifying questions
Catalog what you know
Make equation(s)
Think about edge cases to add to equation
**Breakdown components of your"
Exponent - "This is another Fermi problem — an estimation or approximation problem with limited information and back-of-the-envelope calculations. There's no right answer: interviewers want to understand how you think and how well you can explain your reasoning, rather than what you already know.
Recall the formula for Fermi problems:
Ask clarifying questions
Catalog what you know
Make equation(s)
Think about edge cases to add to equation
**Breakdown components of your"See full answer
"Assumption:
question is about people in the US, and we define frequent bar visitor as someone who visits a bar twice a week.
we are defining bars as places that people go for alcoholic beverage , not for the snacks , non alcoholic beverage or sports TV
population of use 330M , 80m per age group
0-20 (eliminate because drinking age is 21 and above)
60-80 (eliminate because they prefer drinks at home or sit down restaurants or are very health conscious to go drinking)
20-30 : 40m
80%"
Ananya M. - "Assumption:
question is about people in the US, and we define frequent bar visitor as someone who visits a bar twice a week.
we are defining bars as places that people go for alcoholic beverage , not for the snacks , non alcoholic beverage or sports TV
population of use 330M , 80m per age group
0-20 (eliminate because drinking age is 21 and above)
60-80 (eliminate because they prefer drinks at home or sit down restaurants or are very health conscious to go drinking)
20-30 : 40m
80%"See full answer
"This is a Fermi problem — an estimation or approximation problem with limited information and back-of-the-envelope calculations. There's no right answer: interviewers want to understand how you think and how well you can explain your reasoning, rather than what you already know.
Recall the formula for Fermi problems:
Ask clarifying questions
Catalog what you know
Make equation(s)
Think about edge cases to add to equation
**Breakdown components of your equat"
Exponent - "This is a Fermi problem — an estimation or approximation problem with limited information and back-of-the-envelope calculations. There's no right answer: interviewers want to understand how you think and how well you can explain your reasoning, rather than what you already know.
Recall the formula for Fermi problems:
Ask clarifying questions
Catalog what you know
Make equation(s)
Think about edge cases to add to equation
**Breakdown components of your equat"See full answer
"Clarifications
Only travellers to be considered? Or should we consider work staff, people who come to receive and see off people when they are traveling? → In essence who is considered to the count? → Assumption, only travellers. If not then you have to consider, staff (ATC, Security, Airlines ground staff, Customs, shop employees, airport staff etc.) making the estimate very difficult, But If I had to guess I would say 5% of total travellers across all the staffing categories.
Estimate"
S H. - "Clarifications
Only travellers to be considered? Or should we consider work staff, people who come to receive and see off people when they are traveling? → In essence who is considered to the count? → Assumption, only travellers. If not then you have to consider, staff (ATC, Security, Airlines ground staff, Customs, shop employees, airport staff etc.) making the estimate very difficult, But If I had to guess I would say 5% of total travellers across all the staffing categories.
Estimate"See full answer
"This is another Fermi problem — an estimation or approximation problem with limited information and back-of-the-envelope calculations. There's no right answer: interviewers want to understand how you think and how well you can explain your reasoning, rather than what you already know.
Recall the formula for Fermi problems:
Ask clarifying questions
Catalog what you know
Make equation(s)
Think about edge cases to add to equation
**Breakdown components of your"
Exponent - "This is another Fermi problem — an estimation or approximation problem with limited information and back-of-the-envelope calculations. There's no right answer: interviewers want to understand how you think and how well you can explain your reasoning, rather than what you already know.
Recall the formula for Fermi problems:
Ask clarifying questions
Catalog what you know
Make equation(s)
Think about edge cases to add to equation
**Breakdown components of your"See full answer
"This is another Fermi problem — an estimation or approximation problem with limited information and back-of-the-envelope calculations. There's no right answer: interviewers want to understand how you think and how well you can explain your reasoning, rather than what you already know.
Recall the formula for Fermi problems:
Ask clarifying questions
Catalog what you know
Make equation(s)
Think about edge cases to add to equation
**Breakdown components of your"
Exponent - "This is another Fermi problem — an estimation or approximation problem with limited information and back-of-the-envelope calculations. There's no right answer: interviewers want to understand how you think and how well you can explain your reasoning, rather than what you already know.
Recall the formula for Fermi problems:
Ask clarifying questions
Catalog what you know
Make equation(s)
Think about edge cases to add to equation
**Breakdown components of your"See full answer
"US Population = 330M
Smartphone users (80 percent penetration) = 264M
Apple has roughly 40 percent market share and Samsung has 30 percent. Pixel has the roughly 2 percent market share.
Total Pixel users = 2 percent of 264M = 5.3M users"
Bipin R. - "US Population = 330M
Smartphone users (80 percent penetration) = 264M
Apple has roughly 40 percent market share and Samsung has 30 percent. Pixel has the roughly 2 percent market share.
Total Pixel users = 2 percent of 264M = 5.3M users"See full answer
"This is another Fermi problem — an estimation or approximation problem with limited information and back-of-the-envelope calculations. There's no right answer: interviewers want to understand how you think and how well you can explain your reasoning, rather than what you already know.
Recall the formula for Fermi problems:
Ask clarifying questions
Catalog what you know
Make equation(s)
Think about edge cases to add to equation
**Breakdown components of your"
Exponent - "This is another Fermi problem — an estimation or approximation problem with limited information and back-of-the-envelope calculations. There's no right answer: interviewers want to understand how you think and how well you can explain your reasoning, rather than what you already know.
Recall the formula for Fermi problems:
Ask clarifying questions
Catalog what you know
Make equation(s)
Think about edge cases to add to equation
**Breakdown components of your"See full answer
"assuming food delivery is about convinience not transport ex: household with working members who own a car might still order in instead of driving. to a restaurant for convenience
excludes tips and taxes
HH = 100M
90% internet penetration
low : mid : high income : 20:50:30
preference for the service 30% (bike service would be slower, one needs to keep that in mind +NY has so many food options , people could cook, meal delivery service, uber eats door dash )
HH with internet penetration that can"
Ananya M. - "assuming food delivery is about convinience not transport ex: household with working members who own a car might still order in instead of driving. to a restaurant for convenience
excludes tips and taxes
HH = 100M
90% internet penetration
low : mid : high income : 20:50:30
preference for the service 30% (bike service would be slower, one needs to keep that in mind +NY has so many food options , people could cook, meal delivery service, uber eats door dash )
HH with internet penetration that can"See full answer