McKinsey Problem Solving Game (Solve): Full Game Reveal

[@Prepmatter]

Access McKinsey Problem Solving Game (Solve) Simulation now: prepmatter.com/online/mckinsey-problem-solving-game

[@TiredParent]

Minor correction: Timestamp 8:52 Shrimp also consumes Red Moss. Not in the graphic drawn with the arrows.

[@Prepmatter]

Thanks for pointing this out. Indeed, shrimp also consumes red moss. As I was drawing the ecosystem, I forgot to draw the arrow from shrimp to red moss. Yet, I've factored this into our calculations.

[@АлександраЗолотарева-о9ь]

@@Prepmatter Why shrimp cannot take 1450 calories from left quantity of sea lettuce (1500), making final number of sea lettuce 50?

[@joshuaoseni]

@@АлександраЗолотарева-о9ь because the remaining calories from it's food source; red moss & sea lettuce, are equal (1500 each after Blue Jellyfish's consumption). Part of the eating rule states that if the calories provided by the food sources are equal, then the predator eats equally from the food sources.

[@TiredParent]

Timestamp 37:24 The question asks, “… if the realistic scenario is realised for all 3 activities”. If this was the case, the likelihood would be irrelevant altogether and a total of 8 + 5 + 4 = 17 species would have been saved. The question should have put the Likelihood percentages given below each graphs into context and how it relates to the animals saved.

[@yomandelamaison9151]

I completely agree... was scrolling through the comments hoping someone would have pointed it out.

[@martinknittel]

Yes, I agree. The wording implies that we shouldn't calculate the expected value (which by the way would include the other scenario) but simply add the species saved as the likelihood is made irrelevant.

[@Captain_Wasabi]

Yup, same here. I was wondering why he multiplied if the prompt assumed it was a given

[@kelvinblueberry1653]

Noticed this too. Not sure if the actual exam is going to have this error as well.

[@willjensen5595]

Thank you! When going through this, I just did the addition and was completely mystified when I saw him calculating the percentages by the amounts.

[@emilabbasov5321]

Amazing video! Passed the McKinsey PSG this week thanks to Deniz's approach. Don't waste time on Excel Solver, just follow Deniz's method!

[@ibrahimmahmoud12]

Did you solve the Redrock lab or Plante defense?

[@emilabbasov229]

@@ibrahimmahmoud12 Ecosystem + Redrock lab + Case

[@preciouslyvivian6466]

Congratulations! Just got the test will be doing it soon too!

[@jeddah_1576]

Hi

[@emilabbasov5321]

@@ibrahimmahmoud12 redrock lab

[@JinJinZhou-c9y]

From my personal experience, while the Prepmatter's simulation does help you understand game mechanisms and overall format of the actual test (having just took the test live), I think there's a few important things to keep in mind (again, personal take so could vary): 1. The ecosystem section is actually a LOT harder in the test as compared to what you might get in the Prepmatter simulation (also with more 3D effects and a slightly different user interface look but no major differences). The reason I say this is because while doing the live test, I realized that there were a lot more "false positives" in the test, which includes "traps" like giving you more choices of species that require HIGH needs, but give LOW provides making it very hard to create a food chain that's more than 2 (ideally 3-4, including the provider as 1). Or, another "trap" would be forcing only a single choice (e.g. a squid can only eat a blue fish); however, the blue fish does not provide ENOUGH calories for the squid which makes it a paradox. I recommend that if you are unable to figure out 8 perfectly working species at the 15 minute mark, it might be a good strategy to keep what you have as backup (write it down on paper, or leave it on the webpage as is) and choose a new depth (the opposite would be best, so if you chose deep, change to shallow). 2. The ecosystem did not include so many indicators for me, what only mattered was the water depth and temperature (only 2), but I am not sure if this might be the case with everyone. 3. The actual case study section has less questions, but is more difficult. The user interface is smoother than in the simulation, and you are also expected to label the data you dragged into your report journal, which is something the simulation does not do. However, I personally found that the case study questions (especially part 2 with the 6 individual cases, which are all stand-alone cases not related to each other) did get increasingly easier. 4. Time management is crucial for case studies, DO NOT spend too much time with the 1st major case, because you'd quickly find that you might only have 15 mins or less left for the remaining 6 stand-alone cases, so try to go in the first major case with 100%, the earlier you finish that the better. 5. Finally, the questions in Prepmatter have absolutely nothing to do with the real test (e.g. Nolotiles, and other data points), so only use the simulator to get a hang of the overal format and flow - don't think that you might run into similar questions in the test because you won't! Good luck to anyone who is planning on playing the Solve Game!

[@HAMZAWORKSOUT]

Do you have a study guide recommendation?

[@kelvinblueberry1653]

Took the McK Solve today. Your methodology for the ecosystem game was spot on. I got the ecosystem right on my first try triple checked everything, and still submitted with 15 minutes to spare. I spent too much time on the first section of RedRock and had only 12 minutes for the 6 questions in the second section. Was able to finish but was not able to double check the 6 case questions. Follow his method for ecosystem game and you will be fine. For redrock, practice time management skills.

[@cheetopancakes]

I am about to take it today, can you help?

[@Prepmatter]

Completely agreed, thanks for sharing your experience with us!

[@joudd6530]

were the questions the same just with different numbers or?

[@unyimeikpeida4577]

Thank you... Taking my test today

[@Priyanka00158]

@@unyimeikpeida4577 How did you do, was it easy?

[@giorgibala7936]

*UPDATE : I got called for an interview* I completed the McKinsey Solve Game. I think it went O.K. The ecosystem to be made was situated in Coral's Reef. I used an Excel file to complete this task. People who: 1. Regularly use Tab + Alt to switch between applications 2. Can type at a solid pace might find my strategy interesting. My strategy was the following: Utilize a pre-made Excel file with as many sheets as there are producer buckets (i.e., '3'). I called these possible buckets A, B and C. So the sheets are named (Coral A), (Coral B), (Coral C). Depending on which test bucket (A/B/C) I chose, I could switch to the correct sheet. This avoids that I have to work on the same sheet, which can be cumbersome if you have picked 2 buckets (based on the rule thumb) that didn't offer a solution (Unfortunately, that happened to me) In Coral A I preliminarly created a table of producer information (9 rows, because there are 9 producers), with only the following fields: Name, Depth, Temperature, Calories Provided. The Depth & Temperature automatically copies to the respective cells of the same bucket. This whole table automatically copies to sheets Coral B & Coral C. Some advice here would be to first skim through each producer and check if there are predators. If that is the case, you can ignore that particular bucket with the corresponding depth-temperature combination. It saves you some time. Also, I gave them some unique identifier (e.g.: P1, P2, ...), as such that I don't have to write the full name of the animal on paper when testing the ecosystem. Then I switched to the animals, for this I also dedicated a table with 10 rows in each sheet (10 rows for 3 sheets = 30 animals), with the following fields: Name, Depth, Temperature, Calories Needed, Calories Provided, Food Sources (full names of Animals). Correct Depth & Temperature already is copied to this table in each sheet. Also a good practice is to give the animals an unique identifier (e.g.: A1, A2, ...) for the same reason as producers. So, I saw a lot of participants that got lucky by simply applying the rule of thumb (i.e., picking the bucket with the MAX Calories Provided), which means they found a feasible solution with their first test bucket. Often, this rule of thumb can also be completely useless. In my scenario, I applied the rule of thumb and after two test buckets I didn't find a solution. However, I still managed to finish the test with 15 minutes left with a feasible solution in my last test bucket. These are my general tips: A. When filling in the information in the Excel for animals, take a good look at the information and skim through it. What do you see? Work from bottom-up, and first identify animals (2/3) that eat the producers. Take a good look at those particular animals while filling in information. In this way, I managed to see that there wasn't going to be a solution for the first test bucket. I saw red flags, such as 2 animals that had a ridiculous amount of calories needed (>6000), predators of producers that just were not going to survive, because the producers didn't offer them the necessary calories. B. To be prepared for worst-case scenarios, utilize the mock simulation of (kzbin.info/www/bejne/bpm5doVubapqpMk) along with the Excel file and set a timer of 35 minutes to finish the task. If you don't make it, reflect on where you can do better and where you can manage time more efficiently. This is what I did. I also found a very useful video that really provides the exact interface that you will see when playing McKinsey's game. Can be helpful if you want to forecast situations: kzbin.info/www/bejne/f3K3mYegm5hkiZI. Concerning, the RedRock study. The questions (4) and cases (6), were really simplistic. However, I must note that you should have a lot of attention for detail and manage your time efficiently. Read the questions twice! (each word matters). Use the tutorial time (not included in the 35 minutes) to read the instructions. I think the phase where it becomes tricky, is when calculating the answers and dragging it to the journal on the right-hand side. When filling in the answers and continuing from Analysis to Review phase, the application automatically saved the answers in my journal (I lost time because of this, since I thought I had to do it myself). If you do not have a lot of time to play around with the drag boxes, please do not hesitate to get pen & paper and write down necessary computations that you don't want to lose. This is important for the reporting phase, because there might be data that you need to fill in, that wasn't part of the Analysis phase. Very odd, but I screwed up with the graph selection. I had to plot a quantitative (discrete/continuous) variable (e.g. number of plants on RedRock) against a time-series dependent variable, so clearly they wanted me to plot the evolution of the number of plants. In this case, a bar chart offers a better perceptual accuracy, but once you choose one graph you cannot go back (that's where I screwed up). I had 3 minutes left to finish the 6 cases, but I managed to finish 3 of them quite easily. Important that you have a basic sense of: - Percentage point differences - Probabilities (Bayes, Independent vs. Dependent events, Addition or multiplication of probabilities, etc.) - Know what these statistical concepts are: median/mode/average - Weighted Average Overall, if the interface for the RedRock study would be more user friendly, you could easily finish this within 35 minutes. It's really the fact that there are small things, trying to distract you. I hope this overview is meaningful. Good luck to everyone!

[@sakshipal2680]

First thankyou for this great information. Could you please tell in redrock, are the question same excluding the values?

[@giorgibala7936]

​@@sakshipal2680The storyline is regarding an objective to increase the # of plants by 30%, so they rolled out a three-step-plan with each step attempting to increase the amount of plants on the RedRock island. First and foremost you should calculate percentages, since it is not straightforward. Plants are divided into three subcategories (forgot the names) and for each of these subcategories they gave the number indicating how much they appear on the island. Now the physical location of the island is also divided into three locations where these plants (i.e., subcategories) reside, so ideally you could make a cross-table (plant category against location) with the cell values being the number of plants in a certain location. I am afraid the storyline varies from applicant to applicant (i.e., it is completely random). ​

[@elenah.7099]

saving

[@julietayoola7913]

Please what was the time frame from the exam to the time they sent a response

[@giorgibala7936]

@@julietayoola7913 Hi! Let's say about 2 weeks.

[@NataP135]

For Redrock Study, case #3. Why did you multiply the expected number of species by the likelihood of realistic outcome? The question asks "... if the realistic scenario realizes for all three activities?" So, considering it is given to us that realistic scenario is being realized, we do not need to include a probability of it.

[@TheDinma1]

12:27 Please, why did you first pick out all your species only based on one monitor(depth level); before going back to make sure they align with other monitors (salt, temperature etc) Considering that we don't have so much time to work with, I feel it would have been better to choose all that in the beginning. What you think?

[@ne4081]

the game allows you to only see 4 monitors at a time so he choose the 4 significant one and that will change over other variables since the number of species are a lot he only scheem through them cheking the significant monitor and after selection he check for the other monitors it for time management

[@jasmitkalra3297]

@@ne4081 ​ why shouldn't we check for all four parameters for the animals and then minimize the animals that dont satisfy the chosen location's conditions. This would help eliminate more animals, narrowing down our list to choose from. Also, this would remove the possibility of us finding out at the end that a given animal doesnt meet the location conditions. What would be the disadvantages of this approach?

[@ranguism]

This is just great, I haven't come across any video that helped to solve the MSG this well, really appreciate these videos Deniz ,

[@xNarutoShippuden]

You did well?

[@hanniking99]

Hey! One question with regards to Question 2 (Redrock Study): You have calculated the percentage change. However, the question was about the percentage POINT change. My approach: for summit depth --> (47-10)/10 = 370% for base depth --> (35-8)/8 = 337.5% Therefore, the percentage POINT difference is 370% - 337.5% = 32.5%

[@Prepmatter]

Well spotted! To avoid confusion, we'll remove 'point' from Prepmatter's simulation.

[@cindyyang9022]

question, at timestamp 9:10 why did we remove spade fish and not sea urchin? since sea urchin has a higher calories to consume, wouldn't it be better to keep spade fish?

[@onomojulie6949]

I'm asking myself the same question...

[@sirgovie]

just took the test, incredible. the ecosystem i used initially didn’t work, turned around and did another one that worked in 13 mins, just on time.

[@fatimazahraech-chikhi5536]

How was the test? I will pass it in 2 days

[@sirgovie]

@@fatimazahraech-chikhi5536 I'd advise that you don't go with the mindset of the ecosystem working at the first try. Practice this video well, make sure you're comfortable with the little calculations. For the redrock, managing your time is super important. don't dwell too long on questions

[@harshpatwari3007]

At 28:44, shouldn't the difference in snow depth at summit between Dec and Apr should be just 42-10=32. There is no mention of difference in 'highest' and 'lowest' snow depth.

[@AndreTop-h2x]

I don't understand why you calculate the percentage differences that way. isn't the correct formula the difference/average of the two times 100?

[@marknoun7512]

exactly! this is all wrong. Can someone provide more input on this?

[@sriharinair227]

I completed the McKinsey Solve Game today! The games I got - Ecosystem Red Rock 1) Ecosystem - Got the mountain terrain Was super difficult, The process I chose was the same - - Select brackets(3) of producers - Eliminate producer brackets, for which even one producer has no consumers. - Then select one bracket from the two left. - Then start filling the animals. - Check which animals satisfy the conditions and which don't. (Calories needed should be 0, Calories provided should not be 0) - If the bracket you selected does not work, move to the other bracket. This approach helped me solve the entire ecosystem. P.S- The first bracket I selected did not work, had to pivot to the other one, with just 10 minutes to go :( Added my final animal at the last minute. This was definitely super stressful. But I think I did well by the end. 2) Red Rock - Investigation phase - Added all data points available - Don't skip on any - Analysis - Go back to the investigation phase whenever needed, do not hesitate to switch - Use the calculator to show that you are active on the screen, avoid calculating on notes, or personal calculator - Drag and drop is time-consuming, I simply typed in the data points. - Report - Was the simplest phase - Pretty straightforward - Please note, that you cannot go back to the investigation phase from the report phase. - Cases - Simply use your math skills - Learn how to do percentage calculations quickly - Read the question twice before attempting, most of the questions are tricky. Can be solved easily. Final remarks - Go through KZbin videos, multiple times. I used the following links, which was super helpful. - kzbin.info/www/bejne/f3K3mYegm5hkiZI - Thank you PrepMatter for this valuable resource. If you have the money, purchasing simulations sold by various vendors would be helpful. I did not buy the same. Finally, I am still waiting for the result, will make edits as I get to know.

[@cheetopancakes]

I am about to do it in a few hours lol, can we dm? I definitely need help

[@Prepmatter]

Thanks for sharing your experience with the community!

[@MsHanih]

@@cheetopancakes hey how was it??

[@unyimeikpeida4577]

I have to take my test today 😂😂😂 Not ready, but I believe in God

[@arifahameliatijani8632]

cant say anything but thank you so much for this video! i hope you’re having a great day too!

[@zazahussain]

Thank you for this! Could you please tell me why we use 27 as the division base instead of 37 (22:50 time stamp) for the snowfall percentage difference question? Would appreciate a prompt response!

[@F0riss]

I have the same question if you figured why please do tell me

[@Prepmatter]

Sure, because the question asked summit to base ratio. So it should be (summit-base)/base. Let me illustrate with an example. If I ask how much higher 12 is compared to 10 in percentage, you'd do (12-10)/10, so 20% higher. I know it's trickly, but hope that helps!

[@Faithfuloliver]

Thank you so much for your response. So in essence, if the question asked was based on to summit ratio, it would have been summit- base/ summit??

[@Faithfuloliver]

Thank you so much for your response. So in essence, if the question asked was based on to summit ratio, it would have been summit- base/ summit??

[@miatownsend6088]

Just took the test for a position in Lima, Peru and got a 3rd game called Sea Study (can't really remember) about combining microbes (each with 3 numeric characteristics and 1 trait) to to design treatments for 2 contaminated sites. Heads up for anyone taking the Solve in the upcoming days!!! my recommendation would be to have a range of values as you will have to average them later.

[@MsHanih]

any resposnse?

[@camigoool]

Hola! Entonces tuviste 3 juegos: Ecosystem, Sea study y cuál fue el otro?

[@miatownsend6088]

@@camigoool red rock study

[@mariam7677]

@@miatownsend6088 omg i heard most ppl got only two

[@AgnesJean-db6gj]

Question: Why did you eliminate Spadefish, and not Sea Urchin? Any reason behind it? Thank you for the great video.

[@Yitom1]

Same

[@simbasovetova8338]

Hi, I have had test yesterday and got invitation to PEI. I made ecosystem task in 18 minutes. I had to change some initially chosen participants, which made me feel nervous. But I managed to change them fastly. Thank you so much for your tutorial.

[@antarapanja3247]

Hey, did you find similar kind of calculations or it was different?

[@Sadece-consultingvebanking-f6i]

At 10:04, wouldn't it be strategically better to remove sea urchin from the ecosystem rather than spadefish? Ceteris paribus, spadefish consumes less and the sea fan will have extra calories in its reserve for future consumption by other animals?

[@trader-traitor]

In the Redrock Study, Question 4 of the Analysis, why is the percentage difference calculated the way you did? I would think it is more ((summit-base)/summit)*100%

[@NataP135]

I also noticed that. Overall, the formula for the percentage difference is p=(|a-b|)/((a+b)/2).

[@bavarianherald5332]

Why, in the task about summit depth and base depth (40:25 min), was it originally about April, but then the number 16 was taken from April and later switched to May? The result sheet at the end shows 'May 5+3,' but 5 is a result for May, not April.

[@davidramosll]

What would happen if two species have the same calories provided and they have to eat? And also they share some common preys? Which one would eat first?

[@iamlethibe]

at 22:19, isn't 0 the shallowest snow base depth?

[@uzomaochonogor9248]

Please is there anything we need to consider before choosing any location or we can just choose randomly?

[@Prepmatter]

You may want to briefly scan the species cards first. Often times, more than one location will have a viable solution. In case you cannot find a sustainable ecosystem in your chosen location, it is fine to start from scratch in a different location.

[@stephenpeterwandera9176]

This could not have come at the best time. Thank you for this video!

[@Prepmatter]

You're welcome!

[@jasmitkalra3297]

@@Prepmatter 12:27: why shouldn't we check for all four parameters for the animals and then minimize the animals that dont satisfy the chosen location's conditions. This would help eliminate more animals, narrowing down our list to choose from. Also, this would remove the possibility of us finding out at the end that a given animal doesnt meet the location conditions. What would be the disadvantages of this approach?

[@aanyaagarwal9558]

how do you hover around and select the point for the location? what factors to consider there or do you just randomly select any point and then see it parameters (like depth etc)?

[@TiredParent]

There is some confusion in the Eating Rules under guidance. Timestamp 3:00 I would recommend the following changes in the wording: Para 1: The species with the highest “Calories Provided” eats first…. The animal eats its “Food Source” with the highest “Calories Provided” in the first instance… providing that the “Calories provided” of the prey satisfies the “Calories needed” of the respected Animal. If the Animal is feeding on multiple sources of food, AND they ALL provide equal amount of calories (e.g. Sea Lettuce providing 3000 cal. and Red Moss providing 3000 cal.), then the Animal will eat both prey equally… e.g. 1,500 cal. from each. Para 3: Then the species with the next highest “Calories Provided” eats in the Ecosystem…. If there is a tie between “Calories Provided” for the Animals (e.g. Sea Urchin providing 2,100 cal. and Spadefish providing 2,100 cal.), then no Animal will take priority as the “primary eater” and will therefore split their food source equally. E.g. Sea Urchin and Spadefish both eat Sea Fan, they would fulfil their calorie need by utilising 50% of the prey’s “Calories Provided”. This information is given at Timestamp 9:46 but not included in the Eating Rules under guidelines, or at least clear enough.

[@Prepmatter]

Thank you for your comment. The guidebook of our online simulation reflects of the real assessment.

[@silalahot]

Hey, I have a quick question on 21:37. The question is asking us to analyze BETWEEN December and April, but you include december in your analysis. I'm just a bit confused bcs I initially thought that the word 'between' means that we need to exclude December and April on our calculation (i think it'll be more suitable if the questions ask us to analyze FROM December TO April).. looking forward to your answer.. thanks

[@Prepmatter]

Thanks for your question! In a business context, 'between' two time periods includes both periods. For example, if we need to analyze how a company performed between 2020 and 2023, we examine the financials of 2020, 2021, 2022, and 2023. Hope that clarifies things!

[@ahmadmurad-fl2yb]

At 23:43, The percentage decrease should be (19-23)/19 *100 >>> (New-old)/old* 100. Please correct me if Im wrong

[@yummypugs]

no, you can calculate it like this: 23 * x% = 19 and we want to find x%, therefore: x% = 19/23, which is ~82.6%. The reduction is 1-0.826 = 0.174 AKA (1 - 19/23) = (23-19)/23 = 4/23 = ~17.4%

[@prakhar.prakash]

at 8:45 wont blue jellyfish eat sea fan 1st since the producer with highest calories provided is eaten 1st?

[@assermitwally2919]

Hi @prepmatter - thanks for this video. I think there may be a mistake in Question 1 of the Redrock study: The question asks for the difference in SNOWFALL DAYS between the month with the highest AVERAGE SNOWFALL and the month with the lowest AVERAGE SNOWFALL. Doesn't that mean we need to look at the two months with the highest/lowest AVERAGE SNOWFALL and THEN calculate the difference in SNOWFALL DAYS between those two months?

[@Faithfuloliver]

Why do we subtraction 1 to get the percentage in question 4 under the red rock segment

[@Prepmatter]

Oh, that's a method we always use to calculate the percentage difference. For instance, if we want to determine how much higher 120 is compared to 100, we divide 120 by 100, which equals 1.2 or 120%. However, we can't say 120 is 120% higher than 100. Therefore, we subtract 1 (or 100%) from 1.2 (or 120%), resulting in 0.2 or 20%. Thus, 120 is 20% higher than 100. Hope this helps!

[@anandprasad276]

@@Prepmatter Video was very helpful but confused about the percentage difference calculation . Persentage difference of 120 and 100 comes out to be 18.18% ,Please correct me if I'am wrong .

[@tiraminess]

Such a great video. I managed to do the ecosystem game well on my first try with 6 minutes to spare. Follow the method with a pen and paper and calculator, no need for the excel spreadsheet. As for the RedRock study, I just about finished it, but the time management for the cases was quite tricky. Some questions did shock me a bit, but they were simple after I got over the initial panic. Just wanted to thank this guy- regardless of outcome I feel satisfied I did the best I could watching this video :)

[@sakshipal2680]

hii, have you cleared he exam?

[@mariam7677]

hey, i wanted to ask is it allowed to use my own calculator or do i have to use the one on the screen?

[@tiraminess]

@@sakshipal2680 Hi, yes I have

[@tiraminess]

@@mariam7677 Hi, yes you can. For the first ecosystem I'd recommend using your own calculator. For the redrock study, I recommend using the one on screen as part of the assessment score may be based on the calculations you do in which order. Hope this helps!

[@mariam7677]

@@tiraminess thanks

[@tobil0ba]

Thanks for the video! How do you move the solutions to the research journal??

[@TheDinma1]

9:42 URGENT PLEASE ANYBODY🥺 How did you arrive at 775 for each?? I thought the arithmetic will be something like = 1450/2 = 725, then 3000 - 725 from each of the producers. Leaving them with 2275??

[@jasonagholor1145]

No, 1500-725, based on the current calories provided not the initial calories provided, Blue Jelly Fish had already taken 1500 from Red Moss and Sea Lettuce remember?

[@TheDinma1]

@@jasonagholor1145 Thankyou

[@lucksheypahadia3419]

Does including more info in your research journal reduce your points?

[@adiyabiyekenova3938]

Why did you do 47-10 and 35-8 instead of 47-0 and 35-0 for the second question in the Redrock study even though the lowest points were 0?

[@preciouslyvivian6466]

The question requires data between December and April, May and November are not part of it

[@Shynbek]

Thank you for the content! By following your tips, I was able to finish ecosystem task with enough time to triple check calculations. For Redrock, I definitely needed to do more practice questions. Hopefully in less then two weeks I will get a response from the firm.

[@antarapanja3247]

Hey, did you find similar kind of calculations or it was different?

[@NicholasMarin-xl8wg]

I passed the test 2 months ago with the method Deniz showed in the video! By far the most effective and efficient method to pass it. Thanks

[@AkGoyal-d7b]

I gave test today and it consisted of mountain and redrock game. Literally your video helped a lot. Thanks a lot

[@josekellersarmiento941]

In the ecosystem game, what do you recommend to do if we already formed a food web but one of our animals doesn’t comply with the region we selected (ie. different salinity level, different current level, etc)

[@Prepmatter]

The actual game shouldn't be too tricky. Typically, if species meet 1 or 2 criteria in the chosen location, they almost always fulfill the other requirements.

[@jasmitkalra3297]

​@@Prepmatter why shouldn't we check for all four parameters for the animals and then minimize the animals that dont satisfy the chosen location's conditions. This would help eliminate more animals, narrowing down our list to choose from. Also, this would remove the possibility of us finding out at the end that a given animal doesnt meet the location conditions. What would be the disadvantages of this approach?

[@mandisasatimburwa8272]

I took the Game solve this week. And wow your method for the ecosystem worked out! I was able to get through it quickly. Thanks a lot for this! The Reddrock game was a bit confusing my advice- understand the research thoroughly, manage your time effectively practice your maths percentages. This video is the best to get you ready for the game solve. Thank you Denz, keep up the great work!

[@ahmedali-lx5ku]

are the values same even in test?

[@mandisasatimburwa8272]

@@ahmedali-lx5ku No, the values are different.

[@taniyaagrawal1269]

Amazing video! I was able to solve both the games easily well before the time went off. Thanks for explaining it in sucha structured manner!

[@jkalra4512]

Which region did you apply for? Did you get Ecosystem and RedRock? Or another game? Thanks

[@prarupchhaparwal9257]

Are the answers automatically stored in the research journal or do we need to drag them after answering each question? Also, the description for each answer is added automatically or do we need to add it ourselves for reference?

[@Prepmatter]

Yes, your answers are automatically dragged (thankfully!), but you are expected to manually drag other data points into the research journal on your own.

[@pratikshakulkarni566]

Great video! Studied it twice and the assessment went very smoothly 👍🏻

[@SpaceXX71]

Is this the Actual test?

[@pratikshakulkarni566]

Yes. Just different background scenarios for Red Rock. For Ecosystem, I got the Mountain backdrop but principles remain same.

[@Alis.-ij4gt]

​@@pratikshakulkarni566What was the Red Rock about this time ?

[@adebolaoyedele1206]

Your video is so good just finished the assessment and was able to pass the ecosystem game 🙏🏽 thanks a lot...now i await their response

[@ahmedali-lx5ku]

are the values same in the test that is shown in video??

[@adebolaoyedele1206]

@@ahmedali-lx5ku i dont think so and i dont think it's the same animals either

[@sylviaokafor2055]

Did you get red rock or a different game?

[@adebolaoyedele1206]

@@sylviaokafor2055 red rock

[@1Emiloco]

For the ecosystem game I got another working solution. Please let me know if I'm wrong. Great White(6000,4250) - Green Sea Turtle(4400,3000) - Lanternfish(3300,2700) - Shrimp(2750,1450)-(feeds half and half on Sea Lettuce and Red Moss) and Spadefish(2100,2400)-Sea Fan(3500)

[@cristhianmorenoregalado8188]

Thank you very much for your video. I did a good test. Your explanation was tremendously helpful!

[@blessingogegbo3975]

Hello. For choosing the location in the ecosystem creation game, what motivated you to choose the location with >100 depth range. Was this just a random decision? I'll like you to guide me on what to think about before choosing a location, both in the coral reef scenario and mountain ridge scenario. Thank you for this video. It's very helpful!

[@Prepmatter]

It was just a random decision. The species are split evenly into 3 groups of depth/elevation ranges.

[@blessingogegbo3975]

Alright thanks for the response. Also, Sea Urchin and Spadefish had the same calorie provided (2100), with the same food source (Sea Fan) which had 3500 as calorie provided. Then you mentioned, since they both had the same calorie provided, they'd have to consume the food source (Sea Fan) equally. However, Sea Urchin and Spadefish had two different values for their calories needed. Sea Urchin has 3000, and Spadefish has 2400. How did you do the calculation to determine that Spadefish wasn't fit for the food chain? Because from my calculation, If you divide Sea Urchin's calories needed into two (3000÷2 = 1500), then subtract it from Sea Fan's Calorie provided (3500-1500 = 2000). Then do same for Spadefish which has 2400 as calories needed (2400÷2 = 1200). Then subtract it from Sea Fan's remaining calories provided (2000-1200= 800). It shows that there will be 800 calories provided left for Sea Fan which doesn't kill it. So why was Speed fish still removed? I will appreciate your explanation. Thank you.

[@swastikaggarwal221]

thanks sir, I have mckinsey game round in 3 days, is this video enough for practice and crack the game round ?

[@nikkicheon4549]

Could you tell me why you have to remove spadefish instead of Sea Urchin?

[@ju16436]

At 23:45 why do we do 23-19/23 ? Shouldn’t we do 23-19/19 I thought the formula was final value-initial value/initial value ?

[@Prepmatter]

Somebody else asked the same question, sharing below the answer of another user: no, you can calculate it like this: 23 * x% = 19 and we want to find x%, therefore: x% = 19/23, which is ~82.6%. The reduction is 1-0.826 = 0.174 AKA (1 - 19/23) = (23-19)/23 = 4/23 = ~17.4%

[@Aashnaramtri]

@@Prepmatter I didn't quite get it why are we assuming x% ? and why not we can divide the answer by 19

[@vedparulekar478]

Hi! Great Video! Just had a question in the ecosystem game when we start building the food chain, here once you add the first layer of animals and form a sustainable food chain up till that layer and then proceed to add the turtle layer on top and then you check independently just that when the turtle eats does its food source die or not. But shouldn't we check for the entire food chain starting from those species with the highest calories provided and then proceed sequentially to check the sustainability of the food chain? Edit : I know that it works out perfectly in this example, but will it always work out ?

[@joaomiguelresende7936]

I had the same question! Just to be safe, I would recalculate it..

[@animaloverpianist]

Hello! Fantastic and informative video; thank you so much! Question for you: Is it important to show all calculations on the calculator in order to get the highest score? For me, doing 170-150 is easy mental math, as is converting .39 to a percentage. Is it ok to just do that in my head, or do you advise using the calculator for everything? Thank you!

[@Prepmatter]

In this video, we wanted to play it safe and use the calculator every time since the assessment evaluates the candidate’s behaviour. However, we don’t think it would be an issue to perform simple calculations mentally or by pen and paper.

[@apaapabanana]

Just complete my PSG and wanna say thank you for having this walkthrough video, I went through my ecosystem game with no stress and completed within 15 minute. It just that I overspent too much time on using the on screen calculator and understanding the journals for Redrock part, despite the question and the long paragaph is easy. Will update here again if I pass the game and able to proceed to next round. Bless me ✨✨

[@rhodadan5466]

Wish you luck

[@AmeekM]

Any update bro?

[@AmeekM]

Any update

[@apaapabanana]

@@AmeekM I passed the game, but i failed the case interview unfortunately.

[@chesssincerevideosmukulsuh1444]

If there are 3 sets of temperatures and elevations, is it possible to create a sustainable ecosystem in each of these regions, because I believe that you selected the region randomly.

[@jambsanchors]

@prepmatter Are we obliged to select 3 plant species in the ecosystem game ? or we are flexible in choosing 2 plant species and 6 animals ?

[@Prepmatter]

We recommend selecting three plants to simplify the creation of your ecosystem, although you may choose two if you prefer.

[@jambsanchors]

@@Prepmatter Thank you. During testing, we found the following working ecosystem: Great White Shark, Blue Jellyfish, Green Sea Turtle, Loggerhead Sea Turtle, Lanternfish, Red Moss, Sea Lettuce, and Shrimp.

[@simoneaston2524]

In the ecosystem, is it recomendend to check the calories or the environment monitors first?

[@Prepmatter]

Environment monitors, just like 04:06

[@filmmaze]

Hi @Prepmatter @everyone How much decile is required to generally convert an invite? Safe decile number?

[@sakshidhamapurkar1930]

Does anyone have access to excel to solve the game Ecosystem?

[@ClarenceKaranja]

I have waited for this for days😊😊

[@deepansarvan355]

Percentage point difference in differences is 10. Kindly check and confirm. 23:02 Video timing

[@lavalevoo]

Took the test today, the coral reef was very helpful but the redrock was really complicated, hope I’ll pass inshallah even though time wasn’t enought I missed solving the last cae😭

[@MsYasmine1997]

How did it go?

[@ManikumarRajendran]

Nice video! How you calculate the percentage difference?

[@Prepmatter]

((Last value - First value) / First value) - 1 But if you need more clarity on a specific section in the video, let us know!

[@MengGao-iu8mp]

@@Prepmatter "Calculate the difference between the two values, divide by the average of the two values, show that as a percentage", which is what I got when google it. Seems not as the way as you did. Please let me know if I am wrong.

[@jasmitkalra3297]

​@@Prepmatter @28:33: you used (Bigger - Smaller)/Smaller Could you please explain the why you didn't divide by the bigger number i.e. why is the difference relative to the summit and not the base?

[@ice9471]

In the game there are 3 possible combinations, its 3 sets of 13 species. each suited to each other by elevation and temperature. How to identify which one to choose ?

[@isahyazid4446]

21:59 November has the lowest summit depth with 0 inches, its meant to be 47 - 0

[@wiselily]

10:08 Thanks alot!!! I don't understand why Spade Fish was removed. Isn't it true that the ecosystem would survive even if Sea Urchin, instead of Spade Fish, was removed? If that's the case, the remaining calories for the Sea Fan would be 3,500 - 2,400 = 1,100, right?😮

[@miarenauly16]

I think because sea urchin is eaten by more animals vs spade fish. If we watch the next animals he picked, it becomes make sense

[@joudd6530]

why was the lowest base snow depth 8 and not 0?

[@constanzaossa9658]

because it is between december and april

[@unyimeikpeida4577]

So I just watched the entire video for the second time and I must say I feel less pressure and it is clearer now. Just need to brush up on the Redrock Study.... It's a tough one

[@Prepmatter]

Best of luck, and let us know how it goes!

[@abdullahnash5547]

I have a question why would shrimp consume sea lettuce and red moss equally even though they eat sea lettuce only? Thank you

[@Prepmatter]

Thanks for your question; shrimp consume both sea lettuce and red moss actually (as you can see at 07:30 and 09:34). As I was drawing the ecosystem, I just forgot to draw an arrow from shrimp to red moss (thanks for pointing it out!). But I've factored this into our calculations, and hence, the ecosystem is sustainable!

[@abdullahnash5547]

@@Prepmatter thank you so much for your help, effort and the detailed reply.

[@abdullahnash5547]

I have another inqury, should shrimp also get consumed for the system to be more sustainable or is it okay if one species or two are only consuming calories but not consumed as you pointed out on the diagram? In the shrimp case, for example and to elaborate, no other species has any sort of a connection for the shrimp to be consumed unlike the sea urchin where at least it can be eaten by the sea turtle. Thanks in advance@@Prepmatter

[@wolecrowther]

Hello PrepMaster, your tutorial on Ecosystem was top notch. I love your strategy, with it, one doesn't need any excel solver. 1. Pick your location first using one of the producers. 2. Pick producers that have similar characters (elevation,) to the location you have selected. It would be 3 in total l. 3. Then open animals who shared similar characters (elevation) with the selected location, it would be ten in total. 4.Look for animals that feed on the 3 producers. The animals could be like 4. Mind you these animals are selected from the one you have opened. 5. Lastly, look for two animals that feed on the previous four you have selected. It very easy given the strategy the guy taught in this video. However, Red Rock was tough, I couldn't even do the second part of the red rock. Even the first part's answers were not correct 😢

[@cheetopancakes]

I am about to take it today could you help?

[@wolecrowther]

@@cheetopancakes just follow my instructions above.

[@lorenzomantegazza917]

Hi, is it correct to pick the range (meters) in which the total amounts of calories is higher? In the video for istance why did you pick 100-150m?

[@Prepmatter]

It actually makes no difference, there are usually multiple sustainable food chains you can create with any range.

[@ClarenceKaranja]

Thank you for this, couldn't have been more timely 🎉🎉

[@MariaJoseEcheverriBedoya]

Why would you drag the information about the lakes if its not included in the objectives?

[@ahmedali-lx5ku]

is it right the test will have the same values and its exactly the same??

[@akshathmanikandan9732]

why did u choose 'depth range' as opposed to the other major monitors given?

[@Prepmatter]

the species are typically organized across three key depth ranges. So starting with this indicator will help eliminate two-thirds of the potential species.

[@pablocarranzajimenez5978]

What can i do to make sure a location is going to allow me to have a sustainable ecosystem??

[@Prepmatter]

You can always scan the species specifications first, but there is no clear shortcut. In the unlikely case where you cannot find a sustainable ecosystem, it is ok to start from scratch in a different location.

[@Sivagollapalli-kn8jm]

Can anyone explain why to use -1 from the value to get percentage?

[@kaguya1685]

I'm confused why "the month with the least average snowfall" is November (0.3mm) and not May (0.0mm)? Is it because May had 0 snowfall days which means the average would be a division by zero hence undefined hence incomparable?

[@crafty_zaza8004]

Shrimp only eats sea lettuce right? why did you let it consume both sea lettuce and red moss?

[@M-cr1rp]

I have the same question too

[@Prepmatter]

Thanks for your question; shrimp consume both sea lettuce and red moss actually (as you can see at 07:30 and 09:34). As I was drawing the ecosystem, I just forgot to draw an arrow from shrimp to red moss (thanks for pointing it out!). But I've factored this into our calculations, and hence, the ecosystem is sustainable!

[@kevindiaz23]

At 9:36, why do you subtract 4500 - 3000? Why would it not be 3000 - 3000? I thought that the amount of calories consumed was the second number in your parentheses? And that the first number "calories provided" was the amount of calories that that fish would provide another fish if it was consumed?

[@a.a.a000]

exactly my question it should be zero

[@Prepmatter]

If I understood your question, you're asking why we subtracted 1500 from Red Moss and Sea Lettuce (and not 3000 from any of these species). That's because both producers have the same amount of calories provided (3000), so Blue Jellyfish will eat both equally.

[@davidramosll]

What happens if two species have the same calories provided and they both have to eat from common species? What would be the order?

[@saadhamama2112]

is that the real Mck PSG or only sample one ? seems to be quite easy !

[@isavinelli]

Question, at first you said since Blue Jellyfish eats Red Moss and Sea lettuce, we have to assume it eats equally from both, so 1500 each. Why when you are analyzing what Sea urchin will eat, which eats Sea Fan and Sea lettuce, you just take all the calories it needs from one source (Sea Fan) and not considering it taking the 775 calories left from the Sea Lettuce also? Why it is eating the 3000 straight from the Sea Fan? Thanks @prepmatter

[@isavinelli]

@prepmatter

[@angelalugo23]

Do you know if I can take the games in other language that it is not english and if this affects the final score?

[@Prepmatter]

It won't have any impact. We are aware that the game can be played in English, Spanish, Portuguese, or Japanese. McKinsey advises that you should play the game in the language in which you feel most comfortable.

[@errajizakaria-y6g]

@@Prepmatter french is not is the list?

[@Pac-yr5zv]

after finishing ecosystem game i had a video showing 3 species, does that mean only 3 survived?

[@Prepmatter]

I believe you're referring to the actual assessment. After completing the ecosystem creation game, you are presented with animations featuring 3 animals, selected at random. This does not necessarily mean that only 3 animals survived :)

[@Pac-yr5zv]

@@Prepmatterthank you very much, I hope I did everything right! 🤣

[@putrinareswarisularno3297]

@@Pac-yr5zvdid you pass the game?? Can i ask questions regarding the game because I have the game test this week😊thanks in advance!

[@Pac-yr5zv]

@@putrinareswarisularno3297 I’ve taken that test and I’m currently waiting for interviews:) (If I did everything correctly) Feel free to ask about anything that comes to Your mind;)

[@putrinareswarisularno3297]

@@Pac-yr5zv Is the game presented in the video looks the same as the actual assessment? as well as for the ecosystem game, do you recommend choosing the location monitor first or building the food chain first? Thank you

[@julietayoola7913]

Thank you for this material really helped

[@GeorgesElKerr]

Hello, is it going to be the same tasks in the McKinsey game, or do they change it?

[@Prepmatter]

Thanks for your question. If you're asking whether the tasks will be the same as those in the video, they will be different, as we're showcasing scenarios our Prepmatter team created. If you're inquiring whether McKinsey changes the questions periodically, we unfortunately don't have visibility on that.

[@GeorgesElKerr]

@@Prepmatter Thank you for your reply! Do you mean we will have same games but different scenarios?

[@Prepmatter]

@@GeorgesElKerr That's right!

[@RönnRowan]

Is this Red Rock example a real McKinsey Solve version, or very closely similar? I am subscribed to another prep site where they offer a simulation game for Red Rock that appears to be much harder than the example here, and also requires somewhat more complex math. There are 10 cases, and I always run out of time despite finishing the study in less than 20min. Is this video a more accurate representation of the difficulty of the game? If so, I'm much less daunted by this, than the simulation I'm practicing with!

[@RönnRowan]

And another question: is the real Red Rock game thematically similar, ie following nature/environmental topics? The simulation I'm using includes other industries, from aviation to retail.

[@Prepmatter]

Yes, this simulation is a good representation of the real-life assessment. In fact, we’d say the real-life assessment is even easier. Since last year, Redrock Study has reduced the number of cases from 10 to 6. The other resource you have might be outdated. And yes, you should expect ecosystem-related cases in the real-life assessment.

[@s8glow]

For the snow depth level, I can see that the average base snow depth in November is 0, how come we didn't select that as our lowest value when calculating the difference between the highest and lowest base snow depth?

[@Prepmatter]

I believe it was because, in the question, it said between December and April.

[@ezeogborwoji4751]

if the question says "between" November and May, does it not mean that November and May are excluded?

[@yasmineyusuf_]

How much time do I have for the redrock research game? (both studies and cases) @Prepmatter

[@Prepmatter]

35 minutes in total. Feel free to check out our other video to learn more about the game structure: kzbin.info/www/bejne/rpjJfKujp9WcrJo&ab_channel=Prepmatter

[@yasmineyusuf_]

ok thanks! how do i carry out my plan in the tutorial before starting the game? or is this not possible?@@Prepmatter

[@MuhammadKaabBinAbaid]

What does round up to 2 digits mean? Significant figures or decimal points?

[@yusufoladiti7979]

Rounding up to two figures

[@yusufoladiti7979]

Like 2.1398 would be 2.14, 9.786 would be 9.79

[@mohammadibrahim-om9qe]

I liked the video too much. It was really very helpful. I am wishing to practice more on game simulation, but honestly I'm out of money right now. Any suggestion?

[@orlevy68]

Is it possible to copy and paste text in the REAL Redrock test? Can you select and copy text from the questions and paste it elsewhere, or is the screen locked down to prevent copying?

[@lauradiaz6783]

Hi! Can you just type instead of using the calculator or it won't allow you? I rather use the calculator on my phone

[@Prepmatter]

Since your cursor/keyboard activities are also monitored, whenever possible, we advise to use the calculator provided in the game. Also, you can drag datapoints from the research journal to the calculator, and hence, you can avoid making mistakes by using the calculator provided.

[@mohammadibrahim-om9qe]

I have been invited to take the game with a deadline. However I received a rejection email before this deadline and not taking the assessment. How can this happen?

[@Kevin-xs1ft]

that is very odd, did you receive it right before the deadline?

[@mohammadibrahim-om9qe]

@@Kevin-xs1ft I have contacted them. It was a mistake, due to some technical issues faced me and fixed it. I have completed it, but unlikely I hadn't completed the redrock study to the end 😢

[@Kevin-xs1ft]

@@mohammadibrahim-om9qe Oh, I see. I wish you the best brother, I think you still have chance to receive interview, based on what I heard.

[@mohammadibrahim-om9qe]

@@Kevin-xs1ft I hope so 😭😭 time was very stressful

[@mohammadibrahim-om9qe]

@@Kevin-xs1ft Have you done the game before?

[@Nyar.canyada]

Awesome job explaining 🤝 Thank you 🤗 I hope I can use the knowledge gained to Ace my test tomorrow PS: I am definitely sending you a connection request😄

[@AmeekM]

Hi, how was your test! Any update?