Hi, I have practiced and am still practising mental maths but I noticed that, while going through case books that a number of math formulas are required to answer some cases eg, NPV, CAGR, etc. So can I please get a listing of the type of math questions or formulas commonly used for case interviews or general math formulas I should know.

# Maths for cases

Hi,

Here is a set of things you need to know:

**1) Math and formulas:**

- Interest rates calculations
- Compound margin
- NPV using the Rule of 72, Perpetuity
- CAGR using the Rule of 72
- Currencies exchange calculations
- Speed, time, distance calculations
- Equations, systems of equations
- Ratio & Proportions
- Little's Law
- Solving the problems by calculating the area of the triangle
- Profit / breakeven formula
- Correlations, outliers (being able to spot on the graphs, tables)

**2) Fast math skills**

- Rounding up and down
- Learn how to multiply double digit numbers (https://www.youtube.com/watch?v=6ndkkPZYJHo)
- Learn the division table up to 1/11 (i.e. 5/6 = 83.3)
- Learn how to work with zeros using powers (e.g.: 4000000 = 4*10ˆ6)

Use math tools (Mimir math for iOS), Math tool on Viktor Cheng website to practice

**3) Working with tables and graphs and deriving conclusions**

- Study "Say it with Charts" book
- Check all available MBB presentations and publications. Practice to derive conclusions and check yourself with the actual ones from the article / presentation
- GMAT IR part (Official guide and Manhattan prep)
- Learn basic statistics (Any GMAT or MBA prep guides)

Good luck!

(edited)

## Related BootCamp article(s)

## Typical Question Types in Written Tests

Questions among all tests can be categorized in math, GMAT-style, chart reading and brain teaser questions. Each type needs to be approached differently.

4 Comment(s)## How to Read Charts and Data in Case Interviews

We explain and give tips on how to understand and analyze graphs, charts and data presented by interviewer to candidates in case interviews.

5 Comment(s)## Why Math matters

Your math skills will be tested in each and every consulting interview. So you better brush up mental math skills to succeed.

4 Comment(s)## Related case(s)

We are an airline major operating out of India. We want to increase the number of passengers on all our flights. Could you please calculate the financial return of adding one more passenger per flight? Open whole case

Your client, REA, is a reinsurance company. REA recently acquired another reinsurance company (approximatively same size): the choice of this company was notably based on its product portfolio as well as its market presence which appeared complement with REA. However, the acquisition is not well r ... Open whole case