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)

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