Are you having your product manager interview soon? It takes a lot of preparation to rock the typical interview questions. Start with this simple guide to answering quantitative questions by Jackie Bavaro, co-author of Cracking the PM Interview, with an example solution by the Product School.

## The Quantitative Question – *How many dishes get broken per month in San Francisco?*

With this question, the interviewer will assess your analytical skills. Don’t worry too much about getting a right answer because you’ll likely not even be in the ballpark. What matters the most is the process through which you solve difficult problems.

- Start by thinking out loud and asking questions, but choose which ones you’ll ask and which ones you are expected to figure out. Maybe a good starting point is the number of people in San Francisco,
*do you know the population of the city? What is an approximate ratio of people to dishes? What kind of dishes are used in a household? Which situations cause a dish to get broken? Do men break more dishes than women?* - Take a step back and catalog what you know or wish you knew.
*The interviewer told you that San Francisco has a population of around 800,000. You can figure out the number of dishes per person by taking yourself as a benchmark. You are not sure about whether there’s a difference in terms of gender for this problem so you will not consider this variable.* - Use the information you’ve gathered and come up with an equation.

*Broken dishes = Average monthly dishes used in SF * Probability of accident*

Broken dishes = Monthly dish-washing accidents per person * Population of SF

Broken dishes = Unit sales of dishes in SF * % sales due to broken dishes - Estimate, or find ways to estimate the variables in your equation.
*You think that the dishes to individuals ratio is 5:1. You assume that the main cause of broken dishes is accidents during the washing of the dishes which occur once every 2 months.* - Think about corner cases and adjustments.
*Maybe there is an important Greek population in San Francisco; will Greek weddings impact the final result? Is the incidence of broken dishes higher in households with children?* - Break out your math skills and calculate!
- Double check. Think about the number that you’ve gotten as a result.
*Do 600,000 broken dishes per month make sense? Did you under or overestimate something?*

**It might seem challenging to attempt to solve this kind of questions on the spot under a stressful situation. We recommend that you challenge yourself with similar questions and follow these 7 steps. Practice will allow you to tackle these problems with fluency. There’s another critical product manager interview question you need to master, so don’t forget to check out 5 Steps to Tackle the Product Question (With a Sample)**

**If you are interested in learning more about Product Management, we offer an 8-week part-time product management course in San Francisco.**