Estimate the number of Burgers sold in a day at McDonald’s: PM Interview | Guesstimate
Estimate the number of Burgers sold in McDonalds near you.
Aspiring product managers often find themselves facing a unique and challenging question during job interviews: guesstimation.
It’s a term that might sound unfamiliar or even intimidating, but it plays a crucial role in evaluating a candidate’s problem-solving abilities, analytical thinking, and the capacity to make quick, informed decisions — all vital skills for a successful product manager.
Guesstimation is a problem-solving technique that requires candidates to provide a rough estimate or educated guess in response to a quantitative question — often one that seems impossible to answer accurately within the given timeframe.
These questions are designed to assess a candidate’s ability to think critically, apply logical reasoning, and communicate their thought process effectively.
We have created a Guesstimate cheatsheet which will help PMs with the numbers and estimations. If you wish to download it, Comment “Guesstimate Cheatsheet” and will share the link to download. Free for limited time!
Typical guesstimation questions might include:
- “Estimate the number of people in an Airport”
- “Estimate the annual revenue of pizza delivery services in New York City.”
- “How many gas stations are there in the United States?”
Guesstimation questions assess a candidate’s ability to break down a problem, make reasonable assumptions, and arrive at a pragmatic solution.
In our earlier article about Guesstimate we had shared the 4 step technique to solving the guesstimate problem. Do read the article and understand the technique and then continue reading from here.
Now that we have had a basic understanding of guesstimates, here’s a candidates first-hand encounter with a Guesstimate questions in the PM interview.
Estimate the Number of Burgers sold in a day in McDonalds.
Candidate: OK, thats interesting, so here we are estimating the number of burgers sold in a day at McDonalds.
Interviewer: Yes.
Candidate: Which McDonald are we considering? Anyplace specific?
Interviewer: Why would that matter?
Candidate: It would, because if its a bigger McDonalds with much larger capacity to accomodate people then the count would change.
Since the place will have more employees to carter to the customer and faster turn around time.
Interviewer: Consider the McDonalds in your locale.
Candidate: OK, are we considering just the Dine in’s or take away as well?
Interviewer: Both.
Candidate: Ok I believe I have the information I needed before starting the analysis. Here I will be going with the bottom up approach.
I would like to first calculate the number of people that can occupy the seats available at any given time at McDonalds. Then I will evaluate the number of burgers that these people can have.
Also I will calculate separately for Dine-in and takeouts.
Does that sound good?
Interviewer: Yes, go ahead.
Candidate: Ok let me first calculate the number of burger sold in Dine in.
Since we are considering the McDonalds near me, it has the max capacity of around 50.
So at any given time the maximum people that can dine in is 50.
The McDonalds opens at 10 AM and is open till 11 PM.
Here we will define Rush hours and Low footfall hours.
High traffic is when the McDonalds is 100% filled and Low traffic is when the Mcd is 50–60% filled.
I believe the MCD has high traffic from 11 AM to 3 PM and in evening 6 PM to 10PM. Is that a fair assumption?
Interviewer: Yes
Candidate: Ok, Now for one person to eat the burger and leave will take around 15–20 Min. Here I will round it to 20 min. So the turn table time is 20 min i.e for one seat.
So in an hour total people that an eat is 150.
Also around 70% of the people will have a single burger and the 30 % the people with larger appetite will have 2 burger at a time.
Now let us calculate based on these data.
For Rush Hour:
11AM to 3 PM: 4 hours
6PM to 10 PM: 4 hours
Total Rush hour: 8 Hours
Total low traffic hour: 5 Hours
Total Burger in rush hour =
1 Burger consumed + 2 burger consumed
=105*8*1 + 45*8*2
=840 + 720
=1560
Total Burger in Low footfall hours
1 Burger consumed + 2 burger consumed
= 52 *5*1 + 23*5*2
=260 + 230
=490
So the total Burgers sold in Dine in, in a day at McDonalds = 1560+490
=2050 Burgers.
Does this look good?
Interviewer: Yes, go ahead.
Candidate: Now lets calculate for the take aways.
Takeaways can be customer coming to the counter, placing an order and asking it for take away or customer ordering from swiggy, zomato or Doordash.
Here I will count as a total turn around time for both these customers.
Here we will calculate the time taken for MCD to ready the order i.e from cooking, assembly to packing.
Since McD is a QSR which prides itself in fastest turn around time. It would take approximately 5 minutes for each order to be ready.
this is including Billing+ assembly+ packing.
That is 12 take aways in a busy hour.
Similarly for this case we will consider the time for rush hours and the low footfall hours. So the rush hours will have 100% order capacity and low footfall will have 50 % capacity.
Now since its a takeaway, many times the number of burgers ordered per person is more. So here we will consider 50% of orders have 2 burgers, 25% 1 and rest 25% will have 3.
Now lets calculate the number of burgers for takeaways.
Number of burgers in rush hours
= 6*2*8 + 3*1*8 + 3*3*8
=96 + 24 + 72
= 192 burgers
now the number of burger in low footfall hours
= 3*2*5 + 2*1*8 + 2*3*8 (we have considered 2 orders for 1 and 3 burger instead of 1.5 for simpler calculation)
= 30+16+48
=94 Burgers
So the total burgers sold in take away is
=192+94
=286 Burgers.
Does the calculation seems fair?
Interviewer: Yes,
Candidate: Now let me calculate the total number of Burgers sold in a day.
=2050+ 286
=2336 Burgers/day
Interviewer: Do you think this is a right number?
Candidate: If I gut check this, it would be around 180 burgers /hour (dividing 2336 by 13)
Which is 3 burger every minute. Though this might be little on the higher side, but number of burger should be around the same magnitude.
Interviewer: Cool, good approach.
Conclusion:
Candidate here does a good job of breaking down the number, and providing a structure solution and approach.
Guesstimation is not just a quirky interview technique; it’s a valuable skill for product managers.
By mastering the art of guesstimation, you not only increase your chances of acing interviews but also become a more effective problem solver and decision maker in your role.
Remember, guesstimation questions are not about being right; they’re about demonstrating your ability to think critically, analyze data, and communicate effectively — qualities that are essential for a successful career in product management.
So, embrace the challenge, practice regularly, and let guesstimation become one of your secret weapons in your next product management interviews.
