Case math practice

BCG Bain McKinsey
Recent activity on Sep 14, 2020
7 Answers
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Anonymous A asked on May 21, 2020


What're the best resources to practice case interview maths? I'm pretty quick with the mental math aspect of it, however I'd like to practice setting up equations, chart based calculations, breakeven analysis etc. and anything else that might come up under the analysis portion in an interview.


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Content Creator
replied on May 21, 2020
MBB | 100% personal interview success rate (8/8) and 95% candidate success rate | Personalized interview prep
  1. 100% Recommend Rocket Blocks. It's exactly what you're looking for
  2. In addition to that, you can ask other PrepLoungers to case you on chart/math-heavy cases. You can also search for those case types here and work through them yourself.

Just as a reminder, some of the other key formulas you need to know in addition to breakeven are:

  • NPV (with + without growth, perpituity + 1-2 years from now)
  • % Change
  • ROI
  • Margin
  • Markup
  • Inventory turnover
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Content Creator
replied on May 22, 2020
McKinsey / Accenture Alum / Got all BIG3 offers / Harvard Business School


Just download all casebooks available online (tens of them) and go through all math problems they have (Just skip the case solutions and structures). Should be more than enough


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Content Creator
replied on May 21, 2020
McKinsey | Awarded professor at Master in Management @ IE | MBA at MIT |+180 students coached | Integrated FIT Guide aut
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replied on May 21, 2020
McKinsey EM, 8 years recruiting interviews, 4 years professional coaching, 1000+ candidates helped

Hi there! Great you're looking to practice case-based math. I have a few resources I can share, just message me privately & I'll send them along. Best of luck with your prep!

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Saad Ali on Jul 18, 2021

Send you a PM

Content Creator
replied on May 21, 2020
Consultant at BCG Nordics| PE and Due Diligence | BCG London, Boston & Dubai office experience

You can check out rocket blocks. While I have personally not tried it, some of the candidates I have coached have used it and found it helpful. So worth giving it a try

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Anonymous replied on Sep 13, 2020

Dear A,

Basically, it's mostly basic math calculation with some financial formulas. Just keep them in mind:

• Break-even Calculation = Fixed Cost / Contribution Margin; Fixed Cost / (Price – Variable Cost)

• Debt Ratio = Total Debt / Total Assets

• Debt-to-Equity Ratio = Total Debt / Total Equity

• Four Cs (marketing from a customer’s point of view): Convenience, Cost to the user, Communication, Customer needs and wants

• Four Ps (starting or expanding a business): Product, Price, Place, PromotionGross Profit = Sales – Cost of Goods Sold
Gross Profit Margin = Gross Profit / Total Revenue

• Profit = Total Revenue – Total Costs
• Return on Assets = Net Income / Total Assets
• Return on Equity = Net Income / Shareholder’s Equity
• Return on Investment = Net Income / Initial Investment
• SWOT Analysis: Strengths, Weaknesses, Opportunities, ThreatsTotals Costs = Fixed Costs + Variable Costs
• Total Revenue = Price x Volume

Hope it helps



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replied on Sep 14, 2020
Bain | passed >15 MBB interviews as a candidate

Hi Anonymous!

since the math typically done in case is no rocket science, I assume you know how to calculate the typical numbers. For most candidates it's more a question of nervousness and delivering quickly under pressure.

My recommendation is therefore always: expose yourself to the pressure. Pick math-heavy cases and practice them with a candidate peer.

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Ian gave the best answer


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MBB | 100% personal interview success rate (8/8) and 95% candidate success rate | Personalized interview prep
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