# Organizing / Structuring input data for quant problems

Case Interview quant problems Structure
New answer on Oct 05, 2020
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Hello!

I am looking for best practice for better organizing myself during the quant portion of the case interview.

I struggle to effectively organize myself so that I can clearly understand the data and create the equation or structure needed to solve this part of the case. This is especially the case when the interviewer gives a long list of data (instead of showing an exhibit) which I am expected to interpret and utilize to move the case forward.

Could you share your go-to approach for how you organize data given by the interviewer?

Thank you!

M

• Date ascending
• Date descending

Hi,

Use tables for multi-dimensional data.

If the interviewer gives you linear data, you can simply jot it down on the LHS. However, if they say, for example "We have 4 main costs", you better be setting up a table ASAP! Those 4 costs will be your rows, and any additional information given will be in each respective column.

Not only will this help you write down all of the information quickly AND keep track of it, but it will help you figure out where to go next!

By the way, the same applies for exhibits. Write down the key information back onto your sheet!

Hello,

One of the methods that worked for me and for several other people is to take sheet in a landscape format and divide the page in two: on the left you write your structure and the data input you have, and on the left you write the math equations for your calculations. Once you need to start doing the math, you will simply "plug" the numbers from the left side of the page to the right side.

This is a simple method that works for some people, you might develop your own methodology as well.

I hope this helps :)

Mehdi

What works for me is to first define the result you want to calculate. I.e. what is the number you need. Then work backwards, decomposing the number until you arrive at your input numbers to get to a full equation.

For example:

• Say you want to calculate market share of your client in a specfiic niche market, as that is what the interviewer has asked for.
• You know that market share is revenue over total market size
• You can then further decompose, e.g. revenue is the number of items sold multiplied with the price, or revenue per product type summed over all relevant types
• Similarly the market size could be calculated as the sum of all regional markets, or the sum of all competitor's revenues

The last step of course required some intuition on how to track back to your input values. To make sure you have all of them readily available, just write them at the top your page so they won't slip your mind in the stress of the situation.

When you think you have the right equation, a good practice to double check is to plug in the units and see if they all match up in the right way.

At the end, make sure, to take your interview along and explain your approach to them before you actually plug in the numbers and execute the math.

Hello!

This is very very personal and there is no one secret recipie here, but many.

You should find the technique that works for you. In my case, for instance, tables are a way in which I uderstand things very well, but it´s very subjective.

Practice is the only key to success here.

Hope it helps!

Cheers,

Clara