expert
Experte mit der besten Antwort

Francesco

100% Empfehlungsrate

2.865 Meetings

5.792 Q&A Upvotes

349 USD / Coaching

4

Quant skills

Hi guys,

I have my first round McKinsey case interviews (Associate position) coming up at the end of the year. Postponed due to personal reasons -HR asked me to phone in again and book a suitable time later in the year and I am therefore using the time to practise as much as I can.

My problem is I really am not doing well with the quant calculations in terms of knowing the approach to use to solve the case (not framework - mathematical approach). When I look at the answers I ask myself why certain numbers were multiplied/divided as it would never have otherwise occured to me to perform the calculation in that particular method. Can ANYONE please please tell me if this problem is normal and how to go about it. I am beginning to get really discouraged. Ironically I got an A in Math in school (haha) but I cant seem to wrap my head around why some calculations were carried out using the math approach used in the cases(s).

Hi guys,

I have my first round McKinsey case interviews (Associate position) coming up at the end of the year. Postponed due to personal reasons -HR asked me to phone in again and book a suitable time later in the year and I am therefore using the time to practise as much as I can.

My problem is I really am not doing well with the quant calculations in terms of knowing the approach to use to solve the case (not framework - mathematical approach). When I look at the answers I ask myself why certain numbers were multiplied/divided as it would never have otherwise occured to me to perform the calculation in that particular method. Can ANYONE please please tell me if this problem is normal and how to go about it. I am beginning to get really discouraged. Ironically I got an A in Math in school (haha) but I cant seem to wrap my head around why some calculations were carried out using the math approach used in the cases(s).

(editiert)

4 Antworten

  • Upvotes
  • Datum aufsteigend
  • Datum absteigend
Beste Antwort
Coaching mit Francesco vereinbaren

100% Empfehlungsrate

2.865 Meetings

5.792 Q&A Upvotes

349 USD / Coaching

Hi Moji,

it seems your issue is not the math computation, but rather how to structure the math part once you receive a question (that is, the logic behind that you should apply). This means you should not work on your computation skills only, as this is not the reason for the problem. Based on my experience, there might be two reasons for struggling on the math approach, besides lack of computation skills:

  1. You cannot structure the approach due to excessive pressure. Some people can easily find the solution of a math problem when doing that quietly on their own, but are unable to do so once they receive time pressure (eg You have 5 seconds to give me the solution of this – what is 83% of 83?). In this case, I would suggest to cover the problem doing math exercises with a timer, so that you can test yourself with a specific time deadline.
  2. You lack business knowledge of what is the right way to perform math. For example, you don’t know what’s the formula for discount cash flow, price elasticity, etc. In this case, I would suggest to solve the problem reading a good amount of cases, which involves math. You can identify them taking some of the several consulting MBA handbooks online, skim them and stop and read the case when you see some math present. You can then review online the topic you found for further reference. This should give you quickly and for free the right knowledge you need for cases.

Hope this helps,

Francesco

Hi Moji,

it seems your issue is not the math computation, but rather how to structure the math part once you receive a question (that is, the logic behind that you should apply). This means you should not work on your computation skills only, as this is not the reason for the problem. Based on my experience, there might be two reasons for struggling on the math approach, besides lack of computation skills:

  1. You cannot structure the approach due to excessive pressure. Some people can easily find the solution of a math problem when doing that quietly on their own, but are unable to do so once they receive time pressure (eg You have 5 seconds to give me the solution of this – what is 83% of 83?). In this case, I would suggest to cover the problem doing math exercises with a timer, so that you can test yourself with a specific time deadline.
  2. You lack business knowledge of what is the right way to perform math. For example, you don’t know what’s the formula for discount cash flow, price elasticity, etc. In this case, I would suggest to solve the problem reading a good amount of cases, which involves math. You can identify them taking some of the several consulting MBA handbooks online, skim them and stop and read the case when you see some math present. You can then review online the topic you found for further reference. This should give you quickly and for free the right knowledge you need for cases.

Hope this helps,

Francesco

I think you are right on that Francesco. I've been very used to my medical science job that my math has gotten pretty rusty and as you guessed my background is pretty limited. From your experience - how much prep time should I give to get up to speed with the requirements for a first round interview? I've got roughly 10 weeks and wondering if it is even sufficient? — Moji am 3. Sep 2017

Hey Moji,

Congratulations on your 1st round McK.

Regarding the math - since you are already in the first round I'm assuming you went through the McK PST and also having a biomedical background (and having As in Math) I'm assuming math by itself is not the problem.

Usually in a math question during a case there are 3 important moments after understanding the question: (1) coming up with a strategy to solve the problem and communicating said strategy to the interviewer; (2) solving the problem and sharing it with the interviewer; (3) discussing what the result means to the case.

From your comment, I get the problem is in step (1). Now 2 things could be happening: (1) you solve the problem using a different strategy than what is shown in the solutions but reach to the same number (which is perfectly OK and you should not worry about it); and (2) you come to a different number which means your strategy is wrong.

Lets assume (2) is what happens because otherwise there isnt any problem here. There are (3) things you can do to improve your strategy math solving skills:

(1) Do exams similar to the McK PST: This will force you to solve similar type of questions;

(2) Get yourself familiar with all major financial terms and how they relate: this could be one of the sources of your problem since you said you dont know why certain numbers were being multiplied which could mean you dont know the relationship between certain numbers;

(3) Focus on heavy quant. cases in your preparation: As you said you have a couple of months left so by focusing on areas that you feel weak you will bring that area up with time.

Hope this helps!

Hey Moji,

Congratulations on your 1st round McK.

Regarding the math - since you are already in the first round I'm assuming you went through the McK PST and also having a biomedical background (and having As in Math) I'm assuming math by itself is not the problem.

Usually in a math question during a case there are 3 important moments after understanding the question: (1) coming up with a strategy to solve the problem and communicating said strategy to the interviewer; (2) solving the problem and sharing it with the interviewer; (3) discussing what the result means to the case.

From your comment, I get the problem is in step (1). Now 2 things could be happening: (1) you solve the problem using a different strategy than what is shown in the solutions but reach to the same number (which is perfectly OK and you should not worry about it); and (2) you come to a different number which means your strategy is wrong.

Lets assume (2) is what happens because otherwise there isnt any problem here. There are (3) things you can do to improve your strategy math solving skills:

(1) Do exams similar to the McK PST: This will force you to solve similar type of questions;

(2) Get yourself familiar with all major financial terms and how they relate: this could be one of the sources of your problem since you said you dont know why certain numbers were being multiplied which could mean you dont know the relationship between certain numbers;

(3) Focus on heavy quant. cases in your preparation: As you said you have a couple of months left so by focusing on areas that you feel weak you will bring that area up with time.

Hope this helps!

Nuno you basically hit the nail on the head! That's exactly what is frustrating me. Not the math calculations but "how did they even use this method/strategy?" I'll start brushing up my basics and see how far I get. — Moji am 3. Sep 2017

Hi Moji,

Congrats to the McKinsey interviews! I just wanted to tell you that I, even though I have a very quantitative background, also struggled with the maths. What helped me is the extensive practice of the basic math skills with tricks that I saw on the tecmath youtube channel. Then you can use mental math apps or the math section here on preplounge to get better. Once you are more confident with the basics, I found, it is easier to apply it naturally in a business setting.

Good luck, and I am sure you'll do well with enough practice!

Verena

Hi Moji,

Congrats to the McKinsey interviews! I just wanted to tell you that I, even though I have a very quantitative background, also struggled with the maths. What helped me is the extensive practice of the basic math skills with tricks that I saw on the tecmath youtube channel. Then you can use mental math apps or the math section here on preplounge to get better. Once you are more confident with the basics, I found, it is easier to apply it naturally in a business setting.

Good luck, and I am sure you'll do well with enough practice!

Verena

Thanks so much Verena! I'll definitely give it another stab. Hope you got through your interviews :) — Moji am 3. Sep 2017

Coaching mit Vlad vereinbaren

97% Empfehlungsrate

388 Meetings

7.316 Q&A Upvotes

299 USD / Coaching

Hi Moji,

Hi,

Here is how you can improve your math skills. It requires some time so I would try to reschedule your interview and prepare accordingly:

1) Fast math - train, train, and train again

  • Learn how to multiply double digit numbers (google fast math tips)
  • Learn the division table up to 1/11 (i.e. 5/6 = 83.3)
  • Learn how to work with zeros (Hint: 4000000 = 4*10ˆ6)
  • Use math tools (Mimir math for iOS), Math tool on Viktor Cheng website to practice

2) Critical Reasoning

  • GMAT test CR and IR parts (Official guide and Manhattan prep)
  • Mckinsey practice tests
  • PST like tests from the web

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)

4) Case math

  • Practice common market sizing topics (Airport passenger flow, real estate volumes, subway passenger flows, car usage, etc.). You should become comfortable with making assumptions
  • Learn key financial topics (P&L and balance sheet and how to analyze them, Basic Valuation principles via NPV and comps) and case tips (e.g. Rule of 72, Perpetuity)

Good luck with your interviews!

Hi Moji,

Hi,

Here is how you can improve your math skills. It requires some time so I would try to reschedule your interview and prepare accordingly:

1) Fast math - train, train, and train again

  • Learn how to multiply double digit numbers (google fast math tips)
  • Learn the division table up to 1/11 (i.e. 5/6 = 83.3)
  • Learn how to work with zeros (Hint: 4000000 = 4*10ˆ6)
  • Use math tools (Mimir math for iOS), Math tool on Viktor Cheng website to practice

2) Critical Reasoning

  • GMAT test CR and IR parts (Official guide and Manhattan prep)
  • Mckinsey practice tests
  • PST like tests from the web

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)

4) Case math

  • Practice common market sizing topics (Airport passenger flow, real estate volumes, subway passenger flows, car usage, etc.). You should become comfortable with making assumptions
  • Learn key financial topics (P&L and balance sheet and how to analyze them, Basic Valuation principles via NPV and comps) and case tips (e.g. Rule of 72, Perpetuity)

Good luck with your interviews!

Verwandte BootCamp-Artikel

Getting Up to Speed

In order to repeatedly demonstrate prerequisite skills under the pressure of a real case interview, you need to learn the basics and practice cases.

1 Q&A

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.

Interviewer-Led vs Candidate-Led cases

Case Interviews can be led by the candidate or by the interviewer: In Candidate-led cases the main challenge is the structure. In Interviewer-led cases the main challenge is to adapt quickly

Guide to Improving Speed in Written Tests such as the PST

Follow these instructions to significantly improve your performance and speed in solving problem solving tests used at McKinsey, BCG and Bain.

Which companies are currently using written tests ?

All major firms like McKinsey, BCG and Bain use tests to assess a candidate's analytical skills. However the design of those tests can differ a lot.

Verwandte Cases

DHL Consulting case: Books & Codes

55,3 Tsd. mal gelöst
DHL Consulting case: Books & Codes A friend of yours recently got promoted to the position of director of a university library. Yesterday, your friend received a call from the Ministry of Education, who offered him to be part of a national RFID pilot with his library. As your friend is unsure if he should pursue this option, he asks you for your advice. Your task is to assess the RFID technology for his library. How would you approach such a request?
4.6 5 4528
| Bewertung: (4.6 / 5.0)

A friend of yours recently got promoted to the position of director of a university library. Yesterday, your friend received a call from the Ministry of Education, who offered him to be part of a national RFID pilot with his library. As your friend is unsure if he should pursue this option, he asks ... Ganzen Case öffnen

Bain Case: Altes Weingut

53,0 Tsd. mal gelöst
Bain Case: Altes Weingut Sie erben von Ihrem Großvater ein Weingut, die Old Winery, welche sich seit fünf Generationen in Familienbesitz befindet und bis ins 16. Jahrhundert datiert werden kann. Auf den elf Hektar der Old Winery werden konventionell, d.h. nicht biologisch betrieben und zertifiziert, je zur Hälfte weiße und rote Trauben angebaut, wobei der Rebbestand bezüglich Alter und Pflege in gutem Zustand ist. Insgesamt werden nur ¼ der Ernte selbst zu Wein gekeltert; der Rest wird weiterverkauft. Ihr Großvater, der selbst am Image des Weinguts nichts verändern wollte, überließ die Bewirtschaftung und Verwaltung einem jungen dynamischen Winzer. Auf Grund des wenig bekannten Images des Weinguts ist die aktuelle Nachfrage nach dem eigenproduzierten Wein nicht besonders hoch. Da Sie sich mit Weinanbau wenig auskennen, wollen Sie das Weingut nicht operativ leiten, aber finden die Idee spannend, ein Weingut zu besitzen. Ihr Plan ist es jedoch, dem Weingut einen frischen Wind einzuhauchen.
4.4 5 1382
| Bewertung: (4.4 / 5.0)

Sie erben von Ihrem Großvater ein Weingut, die Old Winery, welche sich seit fünf Generationen in Familienbesitz befindet und bis ins 16. Jahrhundert datiert werden kann. Auf den elf Hektar der Old Winery werden konventionell, d.h. nicht biologisch betrieben und zertifiziert, je zur Hälfte weiße und ... Ganzen Case öffnen

zeb case: Quo vadis, Kunde?

49,7 Tsd. mal gelöst
zeb case: Quo vadis, Kunde? Die Bank zum Kurfürst Clemens August, eine national agierende Retail- und Privatkundenbank, ist in einer schwierigen Situation. Die Gewinne sind durch das anhaltende Niedrigzinsumfeld über die letzten Jahre beträchtlich gesunken. Parallel leidet die Bank an einem stetigen Abgang von Kunden. Zusätzlich macht sich der Vorstand Gedanken über die Digitalisierung der Finanzbranche und fragt sich, ob die Bank ausreichend vorbereitet ist.  Analysieren Sie die Situation der Bank und entwickeln Sie eine Lösung, um die Gewinnsituation nachhaltig zu verbessern. Berücksichtigen Sie dabei die Bedenken des Vorstandes in Bezug auf die Digitalisierung.
4.6 5 4230
| Bewertung: (4.6 / 5.0)

Die Bank zum Kurfürst Clemens August, eine national agierende Retail- und Privatkundenbank, ist in einer schwierigen Situation. Die Gewinne sind durch das anhaltende Niedrigzinsumfeld über die letzten Jahre beträchtlich gesunken. Parallel leidet die Bank an einem stetigen Abgang von Kunden. Zusätzli ... Ganzen Case öffnen

DHL Consulting Case: Bike Shop

48,2 Tsd. mal gelöst
DHL Consulting Case: Bike Shop Sie wurden angestellt, um den Besitzer eines Bike-Shops als Unternehmensberater zu unterstützen. Der Bike-Shop hat einen deutlichen Umsatzrückgang im letzten Jahr erlitten. Nun bittet Sie der Besitzer, die Situation und die Optionen für das weitere Vorgehen zu beurteilen. Er will den Gewinn des vergangenen Jahres erfahren, d.h. wie er von dem Umsatzrückgang betroffen wurde, und möchte wissen, was die vorrangigen Maßnahmen sein könnten, um die nächsten Jahre (kurzfristig) zu überstehen. Außerdem möchte er die strategische Wettbewerbsposition des Shops besser verstehen und sucht nach möglichen Wegen, die Umsätze mittel- bis langfristig wieder zu erhöhen.
4.3 5 11176
| Bewertung: (4.3 / 5.0)

Sie wurden angestellt, um den Besitzer eines Bike-Shops als Unternehmensberater zu unterstützen. Der Bike-Shop hat einen deutlichen Umsatzrückgang im letzten Jahr erlitten. Nun bittet Sie der Besitzer, die Situation und die Optionen für das weitere Vorgehen zu beurteilen. Er will den Gewinn des ver ... Ganzen Case öffnen

Oliver Wyman Case: Einrichtung eines Weinkellers

46,5 Tsd. mal gelöst
Oliver Wyman Case: Einrichtung eines Weinkellers Ich denke darüber nach, in meinem Keller einen Weinkeller ein-zurichten. So wie ich das sehe, würde man die Regalfläche in zwei Bereiche aufteilen: (1) einen "Trink"-Bereich, in dem ich Flaschen für den Eigenverbrauch lagere, und (2) einen "Investitions"-Bereich, in dem ich Flaschen lagere, die ich mit Gewinn verkaufen möchte, nachdem sie in einigen Jahren an Wert gewonnen haben. Meine Idee ist es, mit dem "Investitions"-Bereich des Kellers genug Geld zu verdienen, um das, was ich im "Trink"-Bereich verbrauche, mit der Zeit zu finanzieren. Natürlich bin ich durch mehrere Dinge ein-geschränkt: die Menge an Geld, die ich ausgeben kann, die Menge an Wein, die ich trinken kann (oder will), den verfügbaren Platz im Keller und so weiter.
4.3 5 3432
| Bewertung: (4.3 / 5.0)

Ich denke darüber nach, in meinem Keller einen Weinkeller ein-zurichten. So wie ich das sehe, würde man die Regalfläche in zwei Bereiche aufteilen: (1) einen "Trink"-Bereich, in dem ich Flaschen für den Eigenverbrauch lagere, und (2) einen "Investitions"-Bereich, in dem ich Flaschen lagere, die ich ... Ganzen Case öffnen