You guys are fucking retarded, and to prove it I bet none of you can solve this simple af riddle

you guys are fucking retarded, and to prove it I bet none of you can solve this simple af riddle

Other urls found in this thread:

en.wikipedia.org/wiki/Almost_surely
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Homework threads belong in /sci/

ayy lmao

You're fucking retarded it's obvious that they die out

I'd say bout tree fiddy

Every race in the universe is gonna die and go extinct you fucking idiot. Take your homework elsewhere.

If they do not die I will kill them

Shut the fuck up you faggots before I beat your asses with my bat you dumb motherfuckers. You don't who you fucking with bitch faggots.

Assuming immortality other than option A, then 1/4 chance of extinction
Assuming its trick question, the probability is 100% because heat death of the universe

This must be bait, surely you can't be that fucking munted.

There is a higher chance that the aliens will reproduce and continue on.

1/4 chance of dying
1/4 chance of doing nothing
1/4 chance of duplicating
1/4 chance of triplicating

surely there is a bigger chance of it surviving you fucking kindergarden dropout

wrong board

Eat my dick fag.

ohhhh my god for fucks sake, are you a 12 year old?

if so then i'd accept you being this dumb

>25% to die every day
christ
but with 50% that the population grows every day, it's going to be low. If he doesn't die the first day the chance gets progressively smaller, it's 1am and I don't want to come up with the math.

no it's 50/50, because if the alien does nothing then it will die out the next generation

Shut up retard

Well the chance it will die out must be at least 33% because there's a 25% it either dies or does nothing the first day. After that it's honestly impossible to say.

But it can't be 33% because if it does nothing the first day then it can duplicate or triplicate the second day, so it would be less than 33%

If the timeline is infinite, 100%

good, you read the premise and answered the chance for the first day
now answer the problem

Yeah but if it does nothing then it just makes the same four choices the next day. So there's only three choices that matter, meaning the first step won't occur until he picks something that's not do nothing.

but if it does nothing the first day then there is a 0% chance of it going extinct the first day, so if it dies the next day there is a 50% chance of it going extinct

But if the timeline is infinite, then the alien count must also reach the infinity at first

god you guys must feel smug as fuck.

x = (1 + x + x^2 + x^3) / 4
The 3 solutions to the equation are 1, -1 - sqrt(2), and sqrt(2) - 1
The first one obviously can't be the solution since there is a positive chance that the set of aliens survives until infinity, and the second one can't be the solution because it is negative, so it must be sqrt(2) - 1.

If it does nothing day one, and then dies day two, then it's 100% dead (and so is the species since this is the first alien in your proposition) you fucking idiot. Why the fuck do you think it's a 50% chance?

jesus christ Sup Forums

>eventually
>4 equally likely
>for n > 0, "n * n * n ... *n" is nonzero
>all events with P > 0 will occur over infinite trials

Wrong

That's not how probability works idiot. I bet you think that the limit of 1/x as x -> infinity is negative infinity since it is always decreasing.

Well I guess you're the smartest person in this whole board because you can watch a youtube video

Go and make something of yourself you basement dwelling neet

so they will both live and die?

wtf are you saying

Its litteraly 99.9% repeating because assuming they make it past the first day the chance of them dying after that is so small that its pointless

According to my calculations, OP is a fag who should drop out of school to save time.

But there is a 1/4 chance of them all dying any day

per alien
1/4 - death || 3/16 - death + 0-2 || 3/64 || 3/256 ...
1/4 - same || 3/16 - same + 0-2
1/4 - plus one || 3/16 - one + 0-2
1/4 - plus two || 3/16 - two + 0-2

5/16?

I didn't watch a youtube video you fucking idiot this is simple algebra that anyone past 7th grade can do.

What? There can't be a higher chance of them not surviving because the odds of them surviving is so much higher.

There is an option where the alien can become 3 FUCKING ALIENS. TELL ME THAT MEANS THAT THEY WILL GO EXTINCT FASTER

FOR FUCKS SAKE MAN

thank you for proving my point.

i suggest you publish this proof you have of how the probability of an event N, with P > 0 will not occur with 100% probability over infinite trials.

after you don't do this, maybe read this wikipedia page aimed at laymen: en.wikipedia.org/wiki/Almost_surely

i guess i need to spell this out more.

>eventually
So we have infinite time for this to happen.

>4 equally likely
Something has to happen, per the question, so the odds of an alien dying are non zero.

>for n > 0, "n * n * n ... *n" is nonzero
Since the aliens are independent, the odds that an event will happen to every alien are just the compound odds of that happening.

If every alien dies, then they are extinct.

We can determine compound probabilities of this sort by multiplying together the independent probabilities, so we have n*n*n... for as many aliens as there are.

This is guaranteed to be a value greater than zero, given that n is non zero.

>all events with P > 0 will occur over infinite trials
In more rigorous terms, one should say "all possible events occur with probability 100%, over infinite trials". You can read about this concept at the wikipedia page I linked above.

P is not constant you fucking inbred mongrel.

you seem mad about your inability to understand basic concepts in mathematics, like how a number doesn't need to be constant in order to obey a constant property.

100%. Everybody who says otherwise should get a statistics class.

What do you mean the first can't be negative?

It is just the inverse of surviving, so the chance that they die out is -1-sqrt(2)

source: uni stats

You're fucking retarded. You can't even grasp the concept of an event.

this is the correct answer.

Im guessing thr final answer has to have x in it for the amount of days.

1/4+3*(not sure what would go here but it probably involves limits)

posed this to a friend and she came up with a much better solution than me, some googling provides an image which illustrates the point very well.

feels bad that i would fail this question on an interview

It's impossible to answer without information about populations of the species in other places.

Yes, and the chance of that happening is less than worth counting

The answer has already been posted in this thread. Why are people still arguing?

because no one ever reads the thread
ever

this.
source: didn't read thread.

Always gonna die out in infinite generations.

No. Thats not true. They only must die out.

The first or second generation could do it, or with a very low probability the one millionth, but they will die out. The probability that they hit infinity is infinity low, usually modeled as zero.

You're fucking retarded.

but p=1, so p will always be 1

so its a 100% chance they die out

fug is there a way to solve something to the third power analytically?

because it isnt correct for fucks sake

read

Except it cannot be 1. Ever heard of expected value?

You are retarded. Each generation has "a" chance of all aliens dieing in that generation. It gets smaller when there are more aliens, but its always there.

This alone is going to ensure all die already over infinite iterations.

Square root of two minus one

Just like how 1/x eventually will reach negative infinity because every increase in x it goes down right?

There's more than 1 solution though.

And the third one is the correct solution.

With infinite time, the chance that the aliens die out will be 100%.
Every generation the chance of dying out grows a little bit smaller, but it never reaches zero.
The sum of that is still 100%.

100% because of the heat death of the universe.

You're obviously not explaining yourself well enough.

No, that is very unrelated.

lol, there is an error but i think its close
Note that each alien has to die eventually.. if it lives four days it probably was a bit lucky (0.75^4 = 31%) / one in 20 lives 10 days

per alien :
1/4 death (1st step) + 3/16 death (plus 0-2 aliens) + 9/64 death (plus 0-4 aliens) + 27/256 death (plus 0-6) + 81/1024 death (plus 0-8), covers 76%

probably sum{ 1 / 4^n } for n= 1 to inf

The other two obviously can't be solutions to the problem. What else is there to explain?

1.0 is a valid probability

Obviously it isn't obvious. You can't call yourself right unless people understand you.

Not for the constraints of the problem.

0. Ayy lmaos don't exist.

Arts major here. I BTFO'd all of Sup Forums combined

Probability is defined as a value between 0 and 1 you fuckwit.

But 1 isn't a valid solution to the problem.

Explain. It obviously can't be negative but a 100% death rate is possible.

>abusing infinity this much

No, the probability of all aliens becoming extinct in a single generation is what approaches zero but never quite reaches it. Over infinite trials it will 100% happen.

prob. of aliens living can't be 1 because there is a probability that the first alien dies

What is the expected number of aliens after the first day?

Obviously the problem doesn't converge.

PROBLEM SOLVED

If I flip k number of coins on the kth day, starting with k=1, what is the chance that eventually all the coins I flip will end up as heads?

1.5

What is the expected number of aliens after the second day?

9

no wait 3

A solution of 1 would contradict some other things, so 1 is ruled out.

Try again.

9/4

1 ∈ {0,1}
I don't know what you're on about

2.75

Now what is the expected number after the third day?

wait 2.0625

The expected behavior of the population is to grow after each generation, which contradicts extinction with 1.0 certainty of extinction, so you can rule that out.

0*(1/4) + 1*(3/16) + 2*(9/64) + 3*(27/256) + 4*(81/1024) = 1.1 avg babies per alien death?

100% because humans would attack and kill them due to being scared bitches.

aliens dont have babies retard they replicate

t.Trump

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