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Fractions

Math drills have exercises with adding fractions etc.,but I'm not sure I get where to use these during a case. What would be some examples of using fractions to do math easily in a case? 

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Top answer
Andrew
Coach
on Jul 27, 2021
Recent Bain SF | UVa Recruiting Lead | Experienced on Both Sides of the Table

Hi there!

Adding fractions (or percentages) can come up in a variety of case types and consulting situations. An example might be a market share situation (e.g., Company A and Company B supply business customers in the widget retail market, in which 3,000 widgets are purchased by consumers each year. Company A supplies 4 customers which sell 300, 400, 500, and 600 widgets per year respectively, and Company B supplies one customer that sells 1,000 widgets per year; what portion of which customer accounts can or should Company B try to take from Company A in order to get to >50% market share?) or a breakeven situation (e.g., Fixed Costs are X and Variable Costs are Y; Demand will be Z if we price at $A and 1.5x Z if we price at $B. How should we price the product?).

There are a variety of case situations where manipulating fractions may come up. The best approach (e.g., converting to percentages, doing the math in your head, writing it out, etc.) will depend on your skillset and the situation. I would always advise interviewees to simplify their math and never try to do calculations in their heads which they may do incorrectly. Writing it out is rarely a bad move. However, practicing mental math is a great idea regardless!

Hope this helps.

Andrew

Anonymous B
on Jul 27, 2021

I dont think you would ever need to do that. In cases you are only really required to know how to do standard additions, subtractions, multiplications and divisions.

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Ian
Coach
on Jul 27, 2021
Top US BCG / MBB Coach - 5,000 sessions |Tech, Platinion, Big 4 | 9/9 personal interviews passed | 95% candidate success

Hi there,

Honestly, I've never really seen this. It doesn't hurt to practice, but normally fractions will simply be multiplied out against a whole number. Or, rather, they'll be provided as percents.

on Jul 28, 2021
McKinsey | NASA | top 10 FT MBA professor for consulting interviews | 6+ years of coaching

Hi, they are not requested, but sometimes they can help you in running divisions

Best,
Antonello

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