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Brain Teaser Cases

brain teaser
New answer on Aug 18, 2021
2 Answers
1.2 k Views
Anonymous A asked on Aug 18, 2021

Hey guys,

I recently came across this brain teaser sort of case prompt. Can somebody throw some light on how to handle such cases & esp. this one.

Case Prompt

An asteroid is going to hit the earth and destroy 100% of it. You have several options: create a missile to destroy it (blowing it into several particles which will still impact the earth but destroy only 50%), or create a missile to push it out of the way (this only has a 50% chance of working though). Which alternative do you pick?

I do understand that one main purpose of such cases is to check candidate's creativity. But the candidate still has to pick one alternative so how should he/she decide the alternative here?

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Content Creator
replied on Aug 18, 2021
#1 BCG coach | MBB | Tier 2 | Digital, Tech, Platinion | 100% personal success rate (8/8) | 95% candidate success rate

I have a question for you: What's the expected value (EV) in each of these scenarios?

They're the same. As such, no, it's not succifient to lay out estimation of probability.

I have another question for you: did you clarify the objective?

Clarify objective - are we trying to save humanity? Are we ok with living with 50% of the population dead?

It's all about objective here...the rest follows.

I won't provide a further framework as i think you should create it yourself with this objective in it and we'll review :)

Additionally, I've created a case with a very similar sort of dilema/thinking. Try it to see how you might think about the entire problem:

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updated an answer on Aug 18, 2021
Bain | EY-Parthenon | Private Equity | Market Estimates | Fit Interview

I think this is more about  considering the consequences. You should build a decision tree here.

Regarding your thought process, I would expect something around the lines below.

Option 1: What does it mean to be impacted by a 50% smaller asteroid? Annihilation or survival? And what kind of survival? 

Being hit by a 50% smaller asteroid does not mean suffering a 50% smaller outcome. It may mean the exact same outcome (e.g. annihilation) or it may mean a much smaller outcome (some relevant damage but no threat to humankind or to life on earth).

If it makes no difference (between the 100% and the 50% asteroid), option 2 is better as you have a 50% chance of survival. 

If it makes a difference, then you would rather have a 100% chance of survival (even if you have to deal with a tough aftermath) vs. a 50% chance of total destruction.


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Ian gave the best answer


Content Creator
#1 BCG coach | MBB | Tier 2 | Digital, Tech, Platinion | 100% personal success rate (8/8) | 95% candidate success rate
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