Estimation Interview Questions

Fabio E. - "First I would like to ask you some clarifying questions. Timeframe: do we consider a single given day? YES What is the definition of jogger? Running, not walking Is there a minimum distance? NO Do you count only the distance within the perimeter of central park or also the miles getting in and out of CP to my start location? ONLY CP Great, I would like to structure the problem this way. \# of aggregated miles run by jogger in a day in CP = # of joggers per day * av"See full answer

Chelsea F. - "Questions: Are these bikes for personal or commercial use? Or both? For commuting, or should we also include recreational bikes (e.g. mountain bikes?) Should we include stationary exercise bikes, or only those used outside? E-bikes and motorcycles? Are we counting children, or just adults? Should we factor in whether the individual has purchasing power to purchase a new bike? What about renting a bike? Assumptions: Assuming we are sizing the market for personal commuter bicycles f"See full answer

M N. - "I'm assuming we are estimating lyft rides taken for attending Halloween parties since the usual daily ride data is already available. Let's assume Lyft is only available in the US. I'm going to start with US population and then estimate the number of people who might be party goers and then deduce number of rideshare users and then estimate how many of them will use Lyft to take them to and from the Halloween party. There are 300M ppl in US. Lets say I break down age groups 1-20, 20-40, 40-60,"See full answer

Judy W. - "Clarifying questions What do you mean by “mattress”? All types and sizes of mattress? Are we only looking at mattress in the household or includes the service industry? Assumption Assume that we are looking at mattress in the household only. Assume that the number of people who own more than one mattress is negligibly small relative to the total US population. Figure that 20% of people are couple and are sharing beds, and 5% are newborns sleeping with their parents. **Appro"See full answer

Ramesh Y. - "Clarifications: Is it passenger/cargo/defense Answer: Passenger Is it direct or stops included - Direct Last I read London had 80 M passengers annually Per month - 6.7 M Per Day - 220 K Assumption here - London is a hub and it has flights to all continents. Assumptions are the split below Flights to Europe -- 30% Flights to USA -- 20% Flights to Asia -- 30% Flights to Africa -- 10% Flights to Australia -- 10% Dubai is part of Asia - 30% of 220 K is 66K Within Asia - Passeng"See full answer

Reshma R. - "Solution: World population = 8B Assuming 10% of world population does not use detergent( using only soap or using only water) Remaining population = 90/100 * 8B = 7.2B ~ 7B Diving the users into 3 categories Users who wash everyday Users who wash twice a week Users who wash once a week Wash everyday --- Wash twice a week --- Wash once a week Used clothes < Used clothes < Used clothes 5gm --- 10gm --- 15gm (Detergent used"See full answer

Joohi M. - "Assume that US and Japan are exactly opposite to each other. If a flight takes 18 hrs to travel between US and Japan and it moves at approx 600km/hr, then the distance covered is 10,800 Km. This constitutes the semi arc of the circle, so we will double is to calculate full circumference which will be 21,600 km."See full answer

Sangeeta P. - "Since I am residing in Bangalore, I will consider the Bengaluru airport. The airport has 2 terminals. I am going to consider the security scan done at both the terminals for the estimation. Does it include security scans for both international and domestic flights? --> Both The airport crew members and pilots also go through the security scan. So, should I include only them as well or only the passengers in my calculation? --> Only the passengers Number of people going through the security scan"See full answer

Darpan D. - "Clarifying and Assumptions Is there any specific geography we need to restrict to? Assumption: Total worldwide. Is there any specific segment we need to restrict to? Assumption: All segments. Number of users Total worldwide users: 300,000,000 Storage per user Slice the users into 3 segments. Low users 80% Free tier 2 GB per user available Using the 80-20 rule for segmentation. Medium users 10% Basic paid tier 2 TB per user available Usi"See full answer

Anonymous Shrimp - "Let's assume that the school furniture includes Table, Chair and Whiteboard. Now, the first step is to find the number of students in the U.S Let's assume that the population of the U.S is 300M. Let's assume that Americans start education at 5 years old till 25 for undergrad. It means Americans spend 20 years of their life in school. Average living years for people is 80. 20/80 * 100 = 25%. It means 25% of the American population attends college. 25/100*300M = 75M. So, there are 75M students"See full answer

Julien C. - "👇 Your feedback is very much appreciated 👇 Clarifying Questions Should we look at it worldwide or in the USA only? Should we consider all Slack messages? ones that are sent in business-owned workspaces? ones that are sent in other types of communities? We'll give numbers for this scope: worldwide all messages Approach: Nb of users x Nb messages sent by user per hour x Nb hours worked per day Nb of users: 10M Nb of messages per hour: 10 Nb of hours worked per day: 8 So an"See full answer

Saurao D. - "Estimate how many potholes there are across the continental USA. Continental USA=? USA area: 9.834~9 Mn km² Considering 10% constitutes of water bodies Land: 8.1~8Mn km² Land will comprise of residential area, commercial area, inner roads and highways Residential area: 2.5% Commercial area:2.5% Inner roads: 2.5% Highways: 2.5% Barren Land: 30% Forest: 30% Grassland: 30% Highways don't have potholes. Also Barren Land and Forest will not be considered. So, Residential area: 2.5%= 0.2Mn"See full answer

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

RockyBalboa - "Clarifications: Do we consider window for any building or only residences? I will ignore windows in cars for complexity reasons. Pardon my ignorance for not knowing the size and population of Tehran, Would you mind sharing some inputs or is it okay if pick some Randoms? Analysis: Tehran is ~300 sq. miles in terms of land area with an overall population of 9 MM with an average 3.5 members per household. _I will be moving with windows for residences only and then gut check my response"See full answer

Anonymous Muskox - "Clarification Questions Do we need to calculate what we are seeing and processing or we want to process our unconscious thoughts in the memory as well? [You can have ] And we need to calculate the amount of storage for a person in single day? [Yes] For more product management interview experience https://technomanagers101.blogspot.com/ High Level Formula = (24 hours - 6 hours of sleep(assuming no processing))([(4 hours of Concentration)(3.5 GB/hr analogous to movie playing at 108"See full answer

Debajyoti B. - "Assuming we have to consider sms sent by people & not company messages, promotions etc Total population of USA- 300 mil Poverty rate- 10% Remaining 270 mil Avg members per household- 4 Total households- approx 70 mil Kids(25) prefer whatsapp over traditional messaging nowadays unless absolutely necessary, so fo"See full answer

David M. - "Depends on what kind of plans we're talking about and what you mean by "flying"."See full answer

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