Hello learners!

Welcome to the 9th day of the series 30 Days of PM Interview by **Crework**! Yesterday, we discussed the second exercise question for guesstimate interviews. Today, we will practice another one.

But before we start, make sure you are subscribed to us. In case you are not, subscribe to us right now and complete the challenge.

### Guess the numbers 💯

Your practice question for today is:

**Estimate the number of Uber rides per day in Delhi. (Asked in Flipkart interview)**

Now, before we move on to “how should we approach it” part, I want you to try it. Come on, pause here for a while, bring a notebook and pen and try this question.

….

….

….

….

….

Okay, now let’s talk about how we can approach this.

**Step 1: Ask Clarifying Questions**

Do we need to consider only Delhi or Delhi-NCR?

Do we need to consider cabs of all types i.e. Go, Pool, Sedan, XL?

Do we need to consider autos too?

Is this for Weekend or Weekday?

What is the market share of Uber? or should I assume it?

So, for solving this problem, we will estimate daily rides for **Delhi only** for any cab type, not including autos. We will consider uniform demand and supply for the day. And market share of Uber is assumed to be 50%.

**Step 2: Coming up with an equation**

So, I am gonna take this approach:

*Number of rides per day = Number of people who book an uber per day * average number of rides per user*

**First, we will calculate the number of people who book a ride per day**

Population of Delhi = 3 Crore

The population can be categorized into 3 parts:

Age < 20 years = 20% = 60 Lakh

Age between 20-60 = 60% =

**1.8 Crore**Age > 60 years = 20% = 60 Lakh

We will assume that the people in the first and third segment don’t take cabs. And not everyone in the 1.8 Crore segment will go out or travel.

Considering only 60% of such people travel, the number of people who travel = 0.6 * 1.8 Crores = 1.08 Crore. Take it 1 crore for simplification

Now, these 1 crore can be categorized further based on their mode of travel preferences:

Doesn’t use any vehicle - 5%

Using metro - 40%

Using other public transport - 25%

Using personal vehicle - 10%

Using private cabs like uber - 10%

Others - 10%

So, only 10 lakh people will prefer taking cab in a day, out of these only 50% will prefer Uber. That gives us the first part of the equation.

*Number of people who book an uber per day = 5 Lakh*

**Now, coming to number of rides**

We can further divide these people based on their frequency of usage:

A) People who book a round trip (people going to office and college) - 60% = 3 lakh

B) People who book only once (going out of city, going somewhere urgently) - 40% = 2 lakh

Number of rides by A segment = 3 lakh * 2 rides = 6 lakh rides

Number of rides by B segment = 2 lakh * 1 ride = 2 lakh rides

Combining them gives us the final answer

**Total rides = 6 lakh + 2 lakh = 8 lakh rides**

This was an example of how you can approach a guesstimate question asked in a PM interview. There can be multiple ways of approaching the same problem, and there is no “right” answer. The interviewer wants to assess your ability to think and come up with a solution. The real answer is the process you use to come up with your solution.

**I would love to see the solution you came up with. Please share it with us on twitter or reply to this mail.**

**Day 9 - Completed ✅**

Congratulations on completing the 9th lesson of the series 30 Day of PM Interview. 🥳

Now, you know what to do. Share your learnings with the world and be accountable.

If you have any feedback, please share it with us. We would love to have your suggestions and improve our content for your better learning.