Guesstimate Interview Questions

I took a bottom-up approach.
Considering an ordinary, urban household with 4 individuals
Number of Maggi needed per month = 10
Therefore, per head consumption = (10/4) = 2.5 Maggi per person
Population = 1.3 billion
Urban population: 70% of total population
Above poverty line population: 40% of total population
Therefore, net population to consider:
1300*0.7*0.4 = 364 million. Population distribution: (Age-wise)
0 – 10 (consume less than 2.5 packets per month, say 2 packets): 20% of the population {which equals to (364*0.2*2) million packets per month = 145.6 million packets per month}
10 – 60 (consume 3 packets per month): 65% of the population {which equals to (364*0.65*3) million kg per month = 709.8 million packets per month}
60+ (consume less than 2.5 packets per month, 2 packets): 15% {which equals to (364*0.15*2) million packets per month = 109.2 million packets per month}
Total approximate consumption = (145.6 + 709.8+109.2) million packets/month = 964.6 million packets/month
Assuming a month of 30 days, per day consumption = (964.6/30) million packets per day = 32.15 million packets per day.

We can approach this problem in two ways:
Demand side
Supply side
I am going to solve using demand of t-shirts in the market
Total population of india : 1 bn (approx) Reach to internet : 40% =400 Mn
Reach of ecommerce companies to deliver products : 3/4th = 300Mn
Let's assume 50% are male and 50% are female
Lets solve for male population first: Now i have divided males in the four categories on the basis of age because demand demand of t-shirts for different age groups will be different
0–15 yr = 45 Mn, on an average, individual own 4 t shirts -> 4*45=180 Mn
16–22 yr = 23 Mn, on an average individual own 4 t shirts -> 4*23 = 92 Mn
23–50 yr = 65 Mn, on an average individual own 3 t shirts -> 3*65 = 195 Mn
50 - 80 yr = 18 Mn, on an average individual have 2 t shirts -> 2*18 = 36 Mn
Total t shirts own by men : 180 + 92+195+36 = 503 Mn ~ 500 Mn
Let's solve for female population now:
0–15 yr = 45 Mn, on an average individual own 2 t shirts -> 2*45=90 Mn
16–22 yr = 23 Mn, on an average individual own 4 t shirts -> 4*23 = 92 Mn
23–30 yr = 15 Mn, on an average individual own 3 t shirts -> 3*15 = 45 Mn
30 - 80 yr = 67 Mn -> we can neglect this section. Only a few ladies prefer to use t-shirts in this age group.
Total t-shirts own by females: 90+92+45 = 227 Mn ~ 230 Mn
Total t-shirts own by men + women = 500+230=730 Mn
Average life of a t-shirt = 2-year
Demand per year = 365 Mn ~ 360 Mn
Online portals provide coupons and offers but because of trust factor and fitting issues, people in India still prefer to buy offline, So I am assuming 30% of people buy a t-shirt from eCommerce portal and 70% are buying from market.
Total number of t-shirts sold through eCommerce platform per year in India= .3*360 = 108 Mn ~ 100 Mn per year
Number of t-shirts sold in India per day(From eCommerce portal) = 100 * 10^6/365 ~ 27,000

The population of India: 1200 mn Population above the poverty line: 70% 840 mn
Population below 14 years: 30%
Hence, proxy figure: 588 mn
Rural Population (70%): 410 mn
Rural Households: 82 Mn
Rural Mobile Penetration: Avg 2 per
household- 164 Mn
In rural areas assume that a new mobile is bought once in 3 years. Hence, new mobiles bought In the current year- 55 Mn Urban (30%):176 Mn
Assume Avg No of Mobiles per person: 1.5
Urban Mobile Penetration: 265 Mn
Assuming that a new mobile is bought once in 1.5 years. Hence new mobiles in the current year- 176 Mn
Total New Mobiles: 231 mn
Assuming 3 out of 10 new mobiles are smartphones
No. of smartphones sold=70 Mn

Observations:
35 million students enroll in India(Undergraduate, graduate, doctorate, diploma)
72% of 35 million graduate every year = 25 million
Students completing 10th grade = 20 million
Students completing 12th grade= 15 million
Unemployed graduates of the previous year= 15 million (Since 60% of 25 million graduates are unemployed)
GDP growth rate is 7%
Calculations:
40% of 25 million graduates are only employed= 10 million
Assuming 500,000 of the previous year’s graduates get a new job
100,000 starts working after 12th grade due to poverty, poor grades, etc
An estimate of 50,000 starts working after 10th grade due to poverty, poor grades, etc
10,000 people already on workforce end up with a new job
Total= 10 million + 500,000 + 100,000 + 50,000 + 10,000 = 10.66 million (approx)
Note:
Migrants working in India are negligible Due to urbanization, very few go for work without completing their 10th grade Increased feminism has a significant effect on the estimates
OYO Rooms Case Study

- The main KPIs for any online room booking company could be:-
a. Online Rating
b. Occupancy %
c. Average daily rate
d. Revenue per available room
e. Customer Satisfaction
f. Advertising ROI