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How can I improve my speed of solving case studies/brainteasers?

Someone asked on Oct 11, 2017 - 1 answer

After 2 weeks of case prep, I am getting more confident in solving case studies and market sizing questions or brainteasers. However, I feel like it takes me way too long to come to the solution.

Does it just take more practise or do you have additional advice on how I can increase my problem solving skills?

Would love to get some feedback on this!

Francesco replied on Oct 12, 2017
#1 Expert for coaching sessions (2.100+) | Ex BCG | 1.000+ reviews with 100% recommendation rate

Hi Anonymous,

there may be several reasons for that; some of them, in order of frequency, are:

  1. Your structure is not complete enough – you are just using not MECE/ not complete structure
    • Solution: Victor Cheng Look Over My Shoulder, MBA Handbooks, PrepLounge Resources section, Expert sessions
  2. You have to develop more business acumen – your structure is fine, however you are unable to brainstorm based on the structure:
    • Solution: case reading, eg from MBA Handbooks, ideally focused on the topic you have to improve
  3. You are unable to prioritize key points in your structure and try to cover all the details eg presenting up to the forth layer in your initial structure
    • Solution: Time yourself when presenting a structure (eg initial one should take max 1.5-2mins) to learn to focus on the essential points only
  4. You are not listening to the hints of the interviewer
    • Solution: Commit to always repeat the question the interviewer is asking
  5. You don’t know how to approach correctly math questions
    • Solution: (i) define the formula you want to use upfront; (ii) verify the formula with the interviewer; (iii) add the numbers just once the forumla has been verified. If you are slow on the math part, train on percentages/divisions in particular
  6. Your framework is MECE but you are unable to eliminate useless branches of the framework
    • Solution: learn how to draw a more clear issue tree, commit to an area and graphically eliminate it each time you find it is a dead end
  7. You lack live case interview experience. All the previous points are fine, but you just spend a lot of time in writing down your approach, considering the best option, eliminate areas, etc due to lack of live experience and/or pressure.
    • Solution: P2P interviews on PrepLounge



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