The Birthday Paradox

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  • Опубликовано: 8 июн 2024
  • How many people need to be in a room before there’s a 50% chance that two of them share the same birthday? Is it about 180, since that’s around half of 365? Is it only 100? The real answer is surprisingly much, much smaller.
    If you have just 23 people in a room, the odds of whether two get presents on the same day is a coin flip. Get 50 people together and that shared-birthday probability skyrockets to 97%. A handful more and it’s a virtual statistical certainty.
    Really? Yes, really! With the aid of tiny plastic babies and some mathematics, Kevin proves and visualizes this surprising veridical paradox.
    *** LINKS ***
    Birthday Attack Example In Hacking
    • 359 Example of a Birth...
    Birthday Attack Hash Collision
    • Birthday Attack: Hash ...
    Hashing Algorithms And Security - Computerphile
    • Hashing Algorithms and...
    Discussion On The Birthday Attack
    • Discussion on The Birt...
    The Birthday Attack
    danielmiessler.com/study/birt...
    ***********
    Vsauce2 Links
    Twitter: / vsaucetwo
    Facebook: / vsaucetwo
    Hosted, Produced, And Edited by Kevin Lieber
    Instagram: / kevlieber
    Twitter: / kevinlieber
    Website: kevinlieber.com
    Research And Writing by Matthew Tabor
    / matthewktabor
    Huge Thanks To Paula Lieber
    www.etsy.com/shop/Craftality
    Get Vsauce's favorite science and math toys delivered to your door!
    www.curiositybox.com/
    Select Music By Jake Chudnow: / jakechudnow
    MY PODCAST -- THE CREATE UNKNOWN
    / thecreateunknown

Комментарии • 34 тыс.

  • @Vsauce2
    @Vsauce2  5 лет назад +26533

    Hey I just recently passed 4 million subscribers and just wanted to thank each and every one of you!!! Now if you'll excuse me I have a cup of babies to finish drinking.

    • @bronsonsnip0r
      @bronsonsnip0r 5 лет назад +54

      the bitdefender link is not working for me :(

    • @PunishedSenp
      @PunishedSenp 5 лет назад +51

      No problem, you deserve it

    • @ukrolelo
      @ukrolelo 5 лет назад +16

      @@bronsonsnip0r me2

    • @kumoriani
      @kumoriani 5 лет назад +59

      You're pretty much the new Vsauce anyway, might as well drop that 2 and make it official

    • @gamemak0r
      @gamemak0r 5 лет назад +56

      Hey if I'm born 1/1/1990 1AM GMT +13 and someone is born simultaneously in a different part of the world 31/12/1989 GMT -12 who is older?

  • @mkaylaC1622
    @mkaylaC1622 3 года назад +16377

    I feel like I just learned everything and forgot everything at the same time

    • @zebmiller510
      @zebmiller510 3 года назад +182

      Welcome, good sir, to Vsauce

    • @geraldbal7945
      @geraldbal7945 3 года назад +54

      damn my neurons just grew exponentially!

    • @supplant9124
      @supplant9124 3 года назад +84

      School basically

    • @el.tubenJr
      @el.tubenJr 3 года назад +23

      I watch to much stuff to keep up with it

    • @gizmofn1957
      @gizmofn1957 3 года назад +17

      That what it's like taking acid

  • @maverick-rs
    @maverick-rs 4 года назад +7026

    Teacher: I have a math problem. Let's say you have 23 babies-
    Me: A problem indeed.

  • @beepduck
    @beepduck 7 месяцев назад +919

    if you are in a room with 50 people, theres a pretty low chance that one of them will share your birthday, but a very high chance that at least two of the other people will have a shared birthday

    • @rajveerkanojiya2985
      @rajveerkanojiya2985 7 месяцев назад +33

      I understood it with the video but whoever can't they gotta look at this comment and now this reply cause
      YOU HAVING THE SAME BIRTHDAY AS THE OTHER PERSON AND BY IT I MEAN YOU HAVING SAME BIRTHDAY EXACT SAME SO THE 50% CHANCE WOULD STILL BE WHEN THERE WILL BE 182 BABIES BUT IN THIS VIDEO THEY ARE NOT TALKING ABOUT YOU SPECIFICALLY THEY ARE TALKING ABOUT ANY 2 PEOPLE OUT OF THOSE 23 I HOPE YOU UNDERSTOOD

    • @ki_yoon
      @ki_yoon 6 месяцев назад +3

      Actually, the probability in that case is about 12%

    • @zaug1561
      @zaug1561 6 месяцев назад +7

      @@ki_yoon 365/50=7.3.....100/7.3=13.6986..... The probability is 13.6986% one of those 50 people will share your birthday.
      Edit: Disregard this, I'm an idiot.

    • @ki_yoon
      @ki_yoon 6 месяцев назад +4

      @@zaug1561 The correct method of calculation is to compute the opposite case and subtract it from 1.
      When there are 50 people, the probability that everyone's birthday is different from you is (364/365)^50 ≒ 87.18%, so the probability that there's someone who has the same birthday as you is about 12.82%

    • @zaug1561
      @zaug1561 6 месяцев назад +4

      @@ki_yoon The chance of 1 person having the same birthday as you is 1 in 365. That seems obvious enough. So the chances of 50 people having the same birthday as you would be 50 in 365. It's that simple.
      Edit: Disregard this, I'm an idiot.

  • @Uri_Cam
    @Uri_Cam 9 месяцев назад +77

    My intrusive toughts are telling me to get 76 people that were born on diffrent days of the year and talk about this video being wrong

    • @Culvers420
      @Culvers420 3 месяца назад +4

      i will support your intrusive thoughts

    • @hv_2911
      @hv_2911 21 день назад +2

      my thoughts exactly :) but realised it would no longer be random as you "selected" people so followed a pattern

  • @aqaisback9517
    @aqaisback9517 2 года назад +14682

    I love when the intros are completely random due to the lack of context.
    “I have 23 BABIES.”

  • @justin8287
    @justin8287 2 года назад +16831

    Man, imagine getting 100 people together to test this theory and then find out no one shares a birthday because you're so unlucky.

    • @fridryx8464
      @fridryx8464 2 года назад +863

      My whole grade when i was in school didnt share a bd the closest was like 1 day apart

    • @RunningPieBOOM
      @RunningPieBOOM 2 года назад +459

      That's more rare so I guess its cooler

    • @cullenpike6314
      @cullenpike6314 2 года назад +343

      Actually that would be extremely lucky bc only like .000001% chance that happens

    • @snipergangdrob5940
      @snipergangdrob5940 2 года назад +174

      @@fridryx8464 My class of 25 has 8/25 kids share a birthday in the 4th grade ofc there was a pair of twins and triplets but 3 other people shared a birthday, (the triplets had a birthday on the same day as some other kid too)

    • @hajilove7337
      @hajilove7337 2 года назад +19

      420 likes. not liking but yeah gagaga

  • @WhiskeyPapa42
    @WhiskeyPapa42 Год назад +47

    I remember doing this as an experiment in a math class with 26 people, and we had 2 sets of duplicate birthdays.

  • @ScKTM68
    @ScKTM68 9 месяцев назад +17

    I had this problem in a statistic exam at computer science university, and yes... they asked us also if this paradox would have been useful for softwares and security was the answer. Very interesting topic

  • @banquo4223
    @banquo4223 3 года назад +43083

    To be fair, they're all babies so I assume their birthdays are fairly close together

    • @anissadunaway5415
      @anissadunaway5415 3 года назад +2795

      good point

    • @leenmutwakil6350
      @leenmutwakil6350 3 года назад +1459

      Smart 🤝

    • @ashokmandal6982
      @ashokmandal6982 3 года назад +737

      No, Even any adult has the same possibilities of the same birthdays as the babies , the possibility is still one of 365

    • @MarkWatney
      @MarkWatney 3 года назад +1022

      In terms of birth year, Yes. In terms of birth date, No.

    • @Neyobe
      @Neyobe 3 года назад +295

      Not really. A baby ranges from 0 days to 2 years old I’d say

  • @aviksheetdasgupta1149
    @aviksheetdasgupta1149 2 года назад +9783

    Kevin : "I've got 23 babies"
    Me : Your wife, how is she ?

  • @alexissliwak9716
    @alexissliwak9716 Год назад +14

    For anyone curious about the formula, it's a simple factorial where you remove lower numbers, keeping the higher numbers starting from 365 as you calculate the chance of NOT getting a matching date.
    For n = # of babies (23)
    And d = # of days (365)
    Chance of 2 with same date:
    = 1 - (d!/(d-n)!) / d^n
    Side note: factorial doesn't work how you would want it to when there is 1 more baby than the number of days(should multiply by 0, but the factorial of 0 equals 1)

  • @JMoney47
    @JMoney47 2 месяца назад +47

    Who here in 2024

  • @-r-3656
    @-r-3656 3 года назад +2529

    “I have 23 babies.”
    *Hold up.*

    • @itsreeya3708
      @itsreeya3708 3 года назад +44

      the fact that this comment has exactly 23 likes... this is what i'm gonna cry about tonight.

    • @user-ju2bk9ut8b
      @user-ju2bk9ut8b 3 года назад +19

      It's true, i was the 23 babies

    • @SaenzGoG
      @SaenzGoG 3 года назад +4

      223 likes, just saying, I love matches.

    • @hugolink0655
      @hugolink0655 3 года назад

      James Bonds constant "woman action" seems to have caught up to him

    • @emegaly1526
      @emegaly1526 3 года назад

      Wait a minute

  • @thejesuschrist
    @thejesuschrist 5 лет назад +53009

    You could say my birthday is a paradox.

  • @Beveyboygames
    @Beveyboygames 2 месяца назад +7

    There is a much better way for explaining this. Pretend you are in a room of 122 people excluding you, now you have a one in three chance of sharing a birthday with another person, because there are exactly as many people as one third the amount of days in a year, which is intuitive and makes sense. Now here's the trick EVERYONE has a one in three chance of sharing a birthday with someone else in this room because of the amount of people, now 99.99997% make more sense in a room of 100 people

    • @nataliawrozek3867
      @nataliawrozek3867 Месяц назад +1

      thank you, I literally struggled with understanding before reading that

    • @Beveyboygames
      @Beveyboygames Месяц назад +2

      @@nataliawrozek3867 yeah it only feels paradoxical if you explain it really weird lol, he probably did it to keep the video going longer

  • @halfcroisant
    @halfcroisant 6 месяцев назад +10

    I respect Kevin for drawing all of those lines just for 5 seconds in a video.
    Also I am born the 11th of March, pls reply. (i know I am late to the party and I know that Mark Rober is born the 11th of March as well)

  • @Grandflea02
    @Grandflea02 2 года назад +5389

    "I've got 23 babies"
    Gengis Khan: *That's cute.*

    • @pointzerovr8516
      @pointzerovr8516 2 года назад +55

      I had to look him up just to know how many kids he had

    • @StolenTorchGuy
      @StolenTorchGuy 2 года назад +20

      @@pointzerovr8516 how many did he have ?

    • @lesymon8483
      @lesymon8483 2 года назад +163

      @@StolenTorchGuy _and he dissapeared, not sharing the number to anyone and leavong the question forever in the darkness..._

    • @thatguykai9140
      @thatguykai9140 2 года назад +32

      @@StolenTorchGuy 14

    • @speedwagon_69
      @speedwagon_69 2 года назад +136

      *he populated the amount he killed*

  • @blackskull7x
    @blackskull7x 3 года назад +13786

    Can't believe I'm watching this for entertainment

    • @aftabhussain4036
      @aftabhussain4036 3 года назад +227

      While having an exam tomorrow

    • @127ante
      @127ante 3 года назад +41

      @@aftabhussain4036 you don’t have winter break?

    • @konosxg7178
      @konosxg7178 3 года назад +25

      Why not??

    • @ComradeHeydi
      @ComradeHeydi 3 года назад +17

      @@127ante yeah? I thought every one did

    • @606movedtonewchannelsaeyou5
      @606movedtonewchannelsaeyou5 3 года назад +14

      @@ComradeHeydi Depends on the country, öy country doesnt have a winter break rn either. It’s ob the 22th January tho

  • @SkibidiToiletSigmaOhioRizzler
    @SkibidiToiletSigmaOhioRizzler 3 месяца назад +4

    0:06 kills me💀💀💀💀💀💀💀💀

  • @chasechamberlain8721
    @chasechamberlain8721 11 месяцев назад +4

    I would like to see 100 people come together and have a unique birthday and they are all one day away

  • @chloroclymor8388
    @chloroclymor8388 4 года назад +4255

    He says “343” right at 3:43
    Coincidence? I THINK NOT

    • @chloroclymor8388
      @chloroclymor8388 4 года назад +129

      Idk

    • @eman210rocks2
      @eman210rocks2 4 года назад +124

      This actually tripped me tf out but maybe that’s just cause it’s 6am

    • @anshulgoyal597
      @anshulgoyal597 4 года назад +74

      or is it???? *raises eyebrow in suspicion*

    • @kevbri11
      @kevbri11 4 года назад +16

      good find my dude

    • @Pablogotthesauce
      @Pablogotthesauce 4 года назад +251

      Also "365" at 4:05 which technically is 3:65

  • @satyakamshashwat
    @satyakamshashwat 3 года назад +2995

    Understood.. so basically, to make sure my password is secure, I should have at least 23 babies...

    • @michalsadlowski1938
      @michalsadlowski1938 3 года назад +10

      Simples!

    • @jasonclarkson3246
      @jasonclarkson3246 3 года назад +36

      Wouldn’t LESS babies be better? Because then there’s less probability of a collision occurring

    • @phjorland
      @phjorland 3 года назад +53

      @@jasonclarkson3246 So you mean I am 100% secure because I don't have children? :D

    • @THEMATT222
      @THEMATT222 3 года назад +3

      @@phjorland LOL

    • @simonpichna4174
      @simonpichna4174 3 года назад +1

      this guy gets it

  • @Tooitoi
    @Tooitoi 9 месяцев назад +6

    Me and my cousin were traveling some years ago and we found a girl who shared same birthday and name as my cousin. What is funnier it that they both lived on the same state, traveled to another country and met at the same place while celebrating their birthdays.

    • @BearPlane747
      @BearPlane747 8 месяцев назад +2

      W profile picture.
      RIP Fly high technoblade. Techno never dies!

    • @craftworld5641
      @craftworld5641 9 дней назад

      I guess they were old twins lost in the crowd🤣

    • @Tooitoi
      @Tooitoi 9 дней назад

      @@BearPlane747 I changed it lmao but glad someone noticed
      techno never dies!!!

    • @Tooitoi
      @Tooitoi 9 дней назад

      @@craftworld5641 yeah it was crazy!! if woulve been even better if they looked alike but the other girl was blonde with blue eyes while my cousin is a tipical latina

  • @tolik_207
    @tolik_207 3 месяца назад +3

    in the whole school, I knew 70 people. and 3 of them had the same birthday

  • @griffincappin8567
    @griffincappin8567 4 года назад +3029

    Nobody:
    People in math problems: I have 23 babies

  • @joshbray5036
    @joshbray5036 5 лет назад +2805

    Worst Villians in 2018
    =================
    2.) Thanos - Wiped out 50% of all living thing
    1.) Kevin - Erased babies

    • @thorjustus5794
      @thorjustus5794 5 лет назад +10

      @Ялимон technically, yes. But it's still sad and mean

    • @pokemonplace8903
      @pokemonplace8903 5 лет назад +4

      0. MF DOOM

    • @porg3354
      @porg3354 5 лет назад +14

      Number 15: Burger King Foot Lettuce

    • @mausam6101
      @mausam6101 5 лет назад +1

      @@pokemonplace8903 0.5 MF Grimm

    • @Calfea
      @Calfea 5 лет назад +1

      Josh Bray lol

  • @lanewisdom6330
    @lanewisdom6330 8 месяцев назад +7

    Damn I always watch videos like this just to get half way and realize I’ve just been daydreaming about something else the whole time, now I have to rewatch it haha

  • @Hussary2004
    @Hussary2004 6 месяцев назад +2

    One of the greatest videos in this great platform

  • @ian8298
    @ian8298 3 года назад +4056

    _this guy:_
    *me:* winning the lotto is 50% chance because you either win or lose

    • @chrisguygamesyt9831
      @chrisguygamesyt9831 3 года назад +170

      Big brain move there

    • @TheAbele992
      @TheAbele992 3 года назад +162

      Lol I always thought as a kid that every single event had a 50% probability: either it happens or it doesn't.

    • @emraldswrd
      @emraldswrd 3 года назад +95

      @HanHanPlayz huh, do u know what chance means lol

    • @miledacruz
      @miledacruz 3 года назад +3

      kinda

    • @N3KLAZ
      @N3KLAZ 3 года назад +7

      @@TheAbele992 mathematically that's actually kinda true

  • @rhinoj
    @rhinoj 2 года назад +2478

    "If we replace our birthday babies with online passwords, . . ." ( 5:18 )
    I didn't expect to hear that sentence today

    • @B3XBP0
      @B3XBP0 2 года назад +30

      Or ever-

    • @kaylynnwalsh3311
      @kaylynnwalsh3311 2 года назад +2

      who did

    • @Penta_I
      @Penta_I 2 года назад +8

      So did "VSauce! Kevin here. *I ' V E G O T T W E N T Y - T H R E E B A B I E S* "

    • @badkarma6392
      @badkarma6392 2 года назад +1

      In my basement 😏

    • @Zielllo
      @Zielllo 2 года назад +1

      So when do you expect it

  • @LotusMouse
    @LotusMouse Месяц назад +2

    Bro was hiding his tears when he erased the 100 baby web thingy

  • @b1oodzy
    @b1oodzy 3 месяца назад +3

    For those that are interested, I ran a code 10000 times that ran the experiment with 23 babies and yes, it does come out to around 50%.
    But what I found more interesting is if we count multiple duplicates that it comes out to around 68%.

    • @MrTrevortxeartxe
      @MrTrevortxeartxe 2 месяца назад

      Multiple duplicates out of how many people?

  • @BlueJay567
    @BlueJay567 3 года назад +3345

    Weird that it seems everyone is getting recommended this right now

    • @uwot9021
      @uwot9021 3 года назад +5

      ye

    • @kayleigh8069
      @kayleigh8069 3 года назад +4

      merry christmas :)

    • @gringerandom5872
      @gringerandom5872 3 года назад +2

      Yeah merry Christmas!

    • @BlueJay567
      @BlueJay567 3 года назад +1

      Thank y’all for the merry Christmas, merry Christmas to you :)

    • @junimeme5626
      @junimeme5626 3 года назад +1

      Probably some weird Christmas timing. Merry Christmas

  • @2acommunity
    @2acommunity 2 года назад +7103

    As a teacher, I confirm this to be true. There is never a year where two students do not share the same birthday.

    • @ts214121
      @ts214121 2 года назад +218

      There were 9 birthday pair matches and a 3-way match in my high school class of about 100 students from over 2 decades ago. I wonder what the typical number is for a group of 100 random people.

    • @obnoxious.
      @obnoxious. 2 года назад +49

      That would mean that there is a 100 % chance, so Vsauce's math is wrong.
      I wish I was your student, I'd have straight As .

    • @ganiz2944
      @ganiz2944 2 года назад +156

      I’ve never had a year where two students did share their birthdays

    • @user-ox5ir2rd6g
      @user-ox5ir2rd6g 2 года назад +17

      @@ganiz2944 horseshit

    • @theloneliestflowerinthefie1938
      @theloneliestflowerinthefie1938 2 года назад +38

      In school I never shared a b. Day with anyone- mine is January 1st

  • @generalludwig1637
    @generalludwig1637 8 месяцев назад +2

    interesting how this also explains how real random shuffles don't "feel" as random with both video game maps and songs....

  • @Speckled_Jim69
    @Speckled_Jim69 4 месяца назад +1

    Here's one for you. When I was 16, I was dating a girl that had the same birthday as me. Same day, month and year. We were both born in the same hospital in a town that had a population of 70,000. I left that town before I went to primary school. So I never meet her until I went back to that town when I was 16.

  • @anthonythompson928
    @anthonythompson928 2 года назад +11781

    Wow. I did this as a fun experiment with some people in an online lobby. Turns out I had the same birthday as my twin brother

    • @makcuja
      @makcuja 2 года назад +372

      Wow so shocking 😱

    • @sam_way2op491
      @sam_way2op491 2 года назад +276

      That's lit bro. Congratulations!!!

    • @jgperes
      @jgperes 2 года назад +53

      Woooow

    • @stevawesome1424
      @stevawesome1424 2 года назад +45

      Lmao

    • @ple8379
      @ple8379 2 года назад +57

      OMG, nooooo! That's so sick, bro!

  • @bunbunnylopunny1565
    @bunbunnylopunny1565 2 года назад +6009

    From a graduating class of around 23 people, the oldest and the youngest shared the same birthday just a year apart. No one else in the class did, just them. Pretty cool.

    • @emilyhellmueller
      @emilyhellmueller 2 года назад +65

      my graduating class has the same situation, but i'm the youngest person! a lot more than 23 people but it's still pretty cool

    • @thextremekittenmdj
      @thextremekittenmdj 2 года назад +27

      wait so how were they in the same grade?

    • @emilyhellmueller
      @emilyhellmueller 2 года назад +41

      @madapult my birthday is august 30 and so was the other girl's. the district allowed anyone to go into that grade as long as their birthday was before september first, but ultimately it's the parent's decision. so technically, she got held back but not really

    • @MarpyPlarpy
      @MarpyPlarpy 2 года назад +43

      @@thextremekittenmdj It is extremely common for people to start school at both the age of 4 turning 5 and 5 turning 6.

    • @InvagPrune
      @InvagPrune 2 года назад +4

      @@emilyhellmueller same in the uk but with August 31

  • @Disblee
    @Disblee 9 месяцев назад +3

    My aunt wanted all her kids to have the same birthday, 2 of them share a birthday, the other 2 are 2 days after the others

  • @JarlHolta
    @JarlHolta 10 месяцев назад +1

    The probability is arguably higher than what you solved for, if we allow cases where we do not "stop at 2", we check further if two other babies have the same birthday in that group as well, and so on.
    Now if we sum it up we end up at 20 people is on average needed to generate a 50.5% chance of shared birthdays, due to multiples groups at times.
    There are other cases as well that can further increase such a number, say 3+ share the same birthday as well.

  • @besmart
    @besmart 5 лет назад +21342

    Kev, I have so much sympathy for you having to write on a dry erase board while left-handed. The struggle, it is real

    • @quolack6435
      @quolack6435 5 лет назад +105

      True, true

    • @GeebleTheGarble
      @GeebleTheGarble 5 лет назад +145

      You realise its the same the other way he just set it up wrong for himself

    • @JakeLovesSteak
      @JakeLovesSteak 5 лет назад +440

      I'm lefthanded, and I'm a teacher. I teach in a classroom with a chalkboard. I've stopped writing on the board as much as possible.

    • @bardsonahill
      @bardsonahill 5 лет назад +47

      It's Okay To Be Smart what makes it harder then for right handed people?

    • @premyaragarla3600
      @premyaragarla3600 5 лет назад +460

      Bards On A Hill We aren’t able to rest our hand on the board, at least comfortably. As you write, you start wiping everything away with you hand because you write left to right.

  • @aboboborinha4811
    @aboboborinha4811 2 года назад +1261

    Imagine him at the store trying to buy this many babies

    • @yangsi3389
      @yangsi3389 2 года назад +2

      🤣😂😂😂😂

    • @cuboembaralhado8294
      @cuboembaralhado8294 2 года назад +18

      they sell in packs of 100, I don't know why

    • @fakefries5238
      @fakefries5238 2 года назад +9

      @@cuboembaralhado8294 theres some funky mexican tradition where a baby that represents baby jesus is put in a cake and whoever finds him throws the baby jesus party next year.
      I'd assume bakers would use them freqeuntly when cooking the baby jesus cakes

    • @cuboembaralhado8294
      @cuboembaralhado8294 2 года назад +1

      @@fakefries5238 oh, ok, that makes sense

    • @RSpracticalshooting
      @RSpracticalshooting 2 года назад

      @@fakefries5238 we had something similar at the catholic elementary school i went to. everybody got a piece of cake and whoever got the baby won a prize.

  • @rufuspipemos
    @rufuspipemos 6 месяцев назад +2

    This explains why, as a kid, I would get many baseball cards of the same player after buying just a few packs, even though there were1,400 players in the MLB.

  • @TranceSFX
    @TranceSFX Месяц назад +1

    It helps greatly to view the day to month conversion table. I.e. day 238 of the year being in August for example.

  • @Alexd0t
    @Alexd0t 3 года назад +5406

    ok so this is crazy, I asked like 9 people and turns out we all had birthdays this year, how do you even explain that?

    • @iamjohn2573
      @iamjohn2573 3 года назад +53

      Where did you ask tho

    • @OhQueBacan
      @OhQueBacan 3 года назад +319

      @@iamjohn2573 lol, it went over your head

    • @nicholasvalentino3291
      @nicholasvalentino3291 3 года назад +171

      Dude this is a next level question

    • @youngpyro9711
      @youngpyro9711 3 года назад +51

      Lmao well worded 😂

    • @alexassassy5855
      @alexassassy5855 3 года назад +48

      @@OhQueBacan he just not misjudging people and taking for acquired the fact that people should be born within a temporal realm rather than chose their identity as a void intemporal protoss goat

  • @Fayrayz
    @Fayrayz 3 года назад +1513

    It took me WAY too long to realize that the babies were actual mini baby dolls and not popcorn. This is what happens when it’s midnight and I’m hungry.

    • @XDlosDominicans
      @XDlosDominicans 2 года назад +75

      they can be popcorn if you want

    • @Jen_TheSnail
      @Jen_TheSnail 2 года назад +81

      Both equally delicious

    • @Fayrayz
      @Fayrayz 2 года назад +15

      @@Jen_TheSnail 0_0

    • @itzjagg5030
      @itzjagg5030 2 года назад +6

      @@Jen_TheSnail @fbi

    • @MissLilyFae
      @MissLilyFae 2 года назад +8

      Big Kronos energy right here

  • @DME3-ms4yz
    @DME3-ms4yz Год назад +2

    Just imagine in a classroom, theres a high probability that your classmates have same birthday and I prove that

    • @minkmiau
      @minkmiau Год назад

      Someone from my 17 people class shares my birthday

  • @rodisfishing1647
    @rodisfishing1647 6 месяцев назад

    this is so fascinating, in 5th grade to up until now (11th) we had from 25-28 students and 2 of those share the same birthday

  • @eben7248
    @eben7248 4 года назад +1173

    “Erasing babies...”
    *“...wait that’s not good”*

    • @Hh-dz3ee
      @Hh-dz3ee 4 года назад +6

      I don’t wanna like cuz then it ruins the 69

    • @icantswim3123
      @icantswim3123 4 года назад +3

      Yes it actually is.

    • @Amdocool
      @Amdocool 4 года назад +2

      My teacher erased my friends hand

    • @lightbombs
      @lightbombs 4 года назад +1

      i also watched the video

    • @davisharper6704
      @davisharper6704 4 года назад

      Well, someone is finally against abortion.

  • @thebookworm1613
    @thebookworm1613 5 лет назад +903

    Breaks a marker drawing the match lines for 23 babies.
    Proceeds to use new marker to draw match lines for 100 babies.

    • @thecyryl
      @thecyryl 5 лет назад +1

      lol

    • @doszlopleonard6031
      @doszlopleonard6031 5 лет назад +1

      For real

    • @jasondeeprose3161
      @jasondeeprose3161 5 лет назад +1

      correct

    • @CapMan275
      @CapMan275 5 лет назад +1

      No because notice no ink was coming out at the end, it was just smearing what was already there.

    • @aamori3036
      @aamori3036 5 лет назад

      Ian Lee that’s because that one probably broke too

  • @lepuluke
    @lepuluke 8 месяцев назад +1

    I still can’t comprehend this. Why is it thou that we have hundreds of friends but no one shares the same birthday?

    • @MonkeShrubb
      @MonkeShrubb 8 месяцев назад

      Incredibly, unimaginably unlucky

  • @the_moons_supernova
    @the_moons_supernova 7 месяцев назад

    this is on my recommended 4 years later

  • @girafpanda8886
    @girafpanda8886 3 года назад +1747

    “BABIES! ERASING BABIES!”
    “Alright that’s not good” lmaoo

    • @I_Cypher
      @I_Cypher 3 года назад +8

      Erasing Babies is a cool band name

    • @ihatesoup9242
      @ihatesoup9242 3 года назад +1

      Ikr

    • @wave._.hunter
      @wave._.hunter 3 года назад +5

      Fetus deletus

    • @Flackzer
      @Flackzer 3 года назад

      @@wave._.hunter lmao

    • @triciavanandler7285
      @triciavanandler7285 3 года назад +1

      Hunter Schoonover I knew that joke would catch up to this eventually

  • @liz-ck9pz
    @liz-ck9pz 2 года назад +514

    man's lost me when he sneaked a ! into the equation

    • @daniaalh1864
      @daniaalh1864 2 года назад +66

      haha the ! means ‘factorial’ - essentially the number multiplied by every number before it. for example 5! is 5x4x3x2x1

    • @Retrenorium
      @Retrenorium 2 года назад +5

      @@daniaalh1864 isn't that the same thing but harder than to simply multiply the current number by the previous result?
      2x1=2
      3!=6 2x3=6
      4!=24 4x6=24
      5!= 120 5x24 = 120
      6! 720 120 × 6 = 600 + 120 = 720
      Etc?

    • @unlqvt
      @unlqvt 2 года назад +14

      @@Retrenorium well yes, thats basically how calculating the factorial recursively works, meaning that you need the previous result in order to be able to calculate the next result.

    • @daniaalh1864
      @daniaalh1864 2 года назад +5

      @@Retrenorium if you’re in the lower numbers then sure but it’s the same thing really. when you get to large numbers like in the question, like 365!, it would be inefficient to sit there doing the work manually when you can use the ! function to get the answer immediately - for reference 10! gives you 3,628,800, so 365! would be an impossibly large number to work with. It also means you don’t have to write 365x364x363… endlessly to get to 1.

  • @brodakarat6340
    @brodakarat6340 11 месяцев назад

    i swear every time ive come across a probability problem that has me stumped, i just negate the thing i want to find out and it becomes trivial

  • @hafplace1346
    @hafplace1346 10 месяцев назад

    thank for explaining the wtf moment i had when i first realised in my class of around 30 i share a birthday with another person, and in my year group of around 180 i share my birthday with 3 people, including the person i first mentioned in my class.

  • @corbanspittka4436
    @corbanspittka4436 3 года назад +651

    Imagine walking into a room with a single light and a man with a table with like a 100 tiny babies in a circle drawing lines....merry Christmas everybody

  • @laloreyes7017
    @laloreyes7017 4 года назад +2068

    me: what’s the wifi password
    friend: it’s on the back of the router
    the back of the router: 6:17

  • @richardfowell490
    @richardfowell490 7 месяцев назад +1

    Think that’s the first time I’ve seen factorial (!) being used since university.
    I’m proud my education has finally come on useful😂

  • @Some_dudelikinggrass
    @Some_dudelikinggrass 5 часов назад

    The reason is, that the 1st child has a 1/365 chance to have the same with the second, while the 3rd has a 2/365, then 3/365 and so on. So it gets more likely to have a match

  • @Milestone783
    @Milestone783 2 года назад +789

    teachers be like: “you didn’t show your work”

    • @venum9663
      @venum9663 2 года назад +58

      “That’s not the correct way of solving the question even though you got the right answer”

    • @emsiyes
      @emsiyes 2 года назад +22

      "And because of that, I'm giving you an F"

    • @speaar
      @speaar 2 года назад +14

      “And that’s why you lost your job”

    • @Kenobisan02
      @Kenobisan02 2 года назад +13

      "The streets are calling my name"

    • @raymiller5895
      @raymiller5895 2 года назад +10

      @@venum9663 I only had one teacher that didn’t do that, she said, “I’ve never seen anyone do it that way before, you got the correct answer. Now let me tell you why that won’t always work. Oh, I’m not marking this as wrong

  • @tigerwoods4034
    @tigerwoods4034 2 года назад +1869

    I went to high school with about 800 guys and everyday during announcements they would shout of the birthdays. It was not uncommon that nobody had a birthday that day. I didn’t know how statistically crazy this was.

    • @nathanbensoni469
      @nathanbensoni469 2 года назад +2

      Hmmmm

    • @stijnkemper7103
      @stijnkemper7103 2 года назад +159

      I rlly need to think to understand this sentence, u could'va said: It was common that nobody had a birthday tbat day😂😂😂

    • @PurpleMoon799
      @PurpleMoon799 2 года назад +19

      probably in august 😉

    • @MaryJane-tp3qd
      @MaryJane-tp3qd 2 года назад +13

      My freshman year had 1,800 kids and now I wish they told us people birthdays :(

    • @HannaSis
      @HannaSis 2 года назад +27

      My school does the same thing and I don’t think that anyone shares the same birthday except for these 3 girls in my class who were all born on the same day, during the same hour 😂

  • @lucasho-hz4tt
    @lucasho-hz4tt 11 месяцев назад +4

    I’m still wondering why he has 75 model babies

    • @plague_doctor-scp-049
      @plague_doctor-scp-049 6 месяцев назад

      i have way more i just see how many i can throw into a cup

  • @CarrotStopper_382
    @CarrotStopper_382 8 месяцев назад +1

    Omg the one time that factorials are ever used

  • @BrooklynBwoii
    @BrooklynBwoii 3 года назад +1430

    As long as 70 people are watching this video at the same time, there is a 99.9% chance that they will have the same death day but in different years.

    • @lunabirdzzz6604
      @lunabirdzzz6604 3 года назад +48

      Dang. That's my only response I can find in my head.

    • @chisinau1302
      @chisinau1302 3 года назад +7

      Now he's more popular, so more people watch the video at the same time.

    • @puginator1612
      @puginator1612 3 года назад +2

      *WHAT*

    • @SkylarGlider
      @SkylarGlider 3 года назад +4

      deep

    • @simbg5146
      @simbg5146 3 года назад +2

      No?

  • @lordjehovah3598
    @lordjehovah3598 5 лет назад +1964

    Vsauce at the shop: Please may I have 75 fake plastic babies please
    Cashier: WTF

    • @geminin6674
      @geminin6674 5 лет назад +10

      Were they bought from a rubber man?

    • @daemichelle
      @daemichelle 5 лет назад +16

      I thought there was 100?

    • @jadenramadhar4340
      @jadenramadhar4340 5 лет назад

      He prob thought of that and ordered it

    • @itsbunnz5295
      @itsbunnz5295 5 лет назад +2

      Btw I just wanna day these baby’s are from a king cake, which is a thing in the south and you find baby’s in it, it’s really weird look it up.

    • @awesomemantroll1088
      @awesomemantroll1088 5 лет назад +18

      He's the guy we read about in math problems

  • @RyanDepauloDegenerateGambler
    @RyanDepauloDegenerateGambler Месяц назад

    It’s like hitting a 23 team parlay on 95+ % favorites so it actually makes sense

  • @barbaquebells2574
    @barbaquebells2574 9 месяцев назад +1

    My old English class assigned seating by birthday. I got close to a kid named Antonio and he had my birthday. On e day we were geeking on that when we realized. The girl next to us, Laura said “That’s my birthday”

  • @Enrique-Garcia
    @Enrique-Garcia 3 года назад +1300

    "So, when were YOU born?"
    Oh no you don't, that's how I was hacked last time...

    • @Steve-mg8tc
      @Steve-mg8tc 3 года назад +8

      69 likes on your comment

    • @Steve-mg8tc
      @Steve-mg8tc 3 года назад +5

      Also I was born April 2 do you happen to be botn the same day

    • @madisonchapman108
      @madisonchapman108 3 года назад +2

      @@Steve-mg8tc I was born on April 3rd lmao

    • @Steve-mg8tc
      @Steve-mg8tc 3 года назад

      @@madisonchapman108 damn

    • @hiimty4986
      @hiimty4986 3 года назад +4

      I’m not relevant but mine is may 17

  • @BAC0NWOW
    @BAC0NWOW 2 года назад +889

    stares into camera... "ive got 23 babies"
    this is why I love vsauce

  • @redrob6026
    @redrob6026 9 месяцев назад

    I once said this fact at a party, and then the first person I asked whose birthday it was had the same birthday as me. Everyone clapped as I walked away.

  • @DBZVelena
    @DBZVelena 6 месяцев назад +1

    so this is why you should use numbers, letters, capitalization and symbols in your passwords.

  • @dylanwoodside3102
    @dylanwoodside3102 4 года назад +2726

    Imagine Kevin going to the store and just buying like 100 tiny babies

  • @violetforyou612
    @violetforyou612 3 года назад +1754

    Me Celebrating Birthday
    Random Strangers around the world:
    *Our Birthday*

  • @jetplanewastaken
    @jetplanewastaken 8 месяцев назад

    0:06 i love the way he just says that nonchalantly

  • @NxnjaSenpai
    @NxnjaSenpai 9 месяцев назад

    Speaking from personal experience. I went to a small high school where each elective class was made up from the same pool of about 50 kids all born within a 6 year range. Not only did the yearbook show that two of my friends shared the same birth day but they both shared the same birth date. They were not related.

  • @wateenabutaha4871
    @wateenabutaha4871 2 года назад +1234

    I did not understand a word besides babies and birthday 👍🏻

    • @evangelinegamali3374
      @evangelinegamali3374 2 года назад +7

      Seseme seed

    • @husseinazher
      @husseinazher 2 года назад +1

      Me2

    • @applepie1272
      @applepie1272 2 года назад +2

      oh Babies and Birthday's are TIGHT

    • @lucytenden7975
      @lucytenden7975 2 года назад

      that’s bc he was trying to make it sound cool and confusing by calling them babies when he rlly means any human not just babies. But if u think about it, obviously there’s a big chance 2 out of 100 people would have the same birthday out of 365 days just not born on the same year.

    • @hicrhodushicsalta4382
      @hicrhodushicsalta4382 2 года назад

      @@lucytenden7975 that's cause it's simple probability (n/k) everyone does this in 9th Grade or so...

  • @kaiserxyozni4786
    @kaiserxyozni4786 5 лет назад +905

    Can we just admire that Kevin literarily purchased 100 baby dolls

    • @dimi7621
      @dimi7621 4 года назад +18

      And also that he gave the effort to put them all one-by-one in place

    • @jadesketch1726
      @jadesketch1726 4 года назад +4

      Do you know where he bought those ?(i want little baby dolls)

    • @nattidahelsinghof2306
      @nattidahelsinghof2306 4 года назад +1

      Jadesketch no but i wan one

    • @payton4786
      @payton4786 4 года назад +7

      you can get them off amazon, all the juniors at my school has littered the school with them

    • @purgatorian1616
      @purgatorian1616 4 года назад +3

      @@payton4786 must've been inspired by Jordan Cunninghams hiding mini babies video

  • @davidloveday8473
    @davidloveday8473 Месяц назад +1

    3:20 is the crucial bit but you suddenly skipped over all the explanations of why the equation should be expressed that way. Why multiply the figures. Why raise the latter figure to a power?

  • @Wisty_Editz
    @Wisty_Editz 7 месяцев назад +1

    That’s why every year in my class, there’s at least 2 people with the same birthday😂

  • @nicholaswensink2314
    @nicholaswensink2314 5 лет назад +574

    A lot of people are misunderstanding this, saying something along the line of “but there are 100 people in my ______ and I share a birthday with none of them”. The probability here is saying there’s a 99.7% chance that at least two in the sample will share a birthday not that you specifically will.

    • @mulymule12
      @mulymule12 5 лет назад +42

      Yeh, make's perfect sense with an ounce of thought. 99.7% chance that 2 will share a birthday in a sample of 100, but that still leaves a 1/50 chance that will be you. Or 2%

    • @azlan194
      @azlan194 5 лет назад +54

      Yeah, a lot of people are confused about it. Another way to put it is like, the probability of SOMEONE winning a lottery this month is very high (almost every month there's someone winning lottery) but the chance of you winning it is almost 0%!

    • @MrHasas963
      @MrHasas963 5 лет назад +2

      The first comment i get. But why did two ppl just confirm what does not need confirming? You you think the guys is right, theres the like button.

    • @MrHasas963
      @MrHasas963 5 лет назад +1

      @@mulymule12 the way i think you should look at it tho is that there is a 50 %chance from your perspective. You will either find one or not. I wouldnt bother because i dont rly want to meet a 100 babies

    • @atriyakoller136
      @atriyakoller136 5 лет назад

      I am a teacher who teaches small groups of students. I have a birthday on December 31st. And in October I had two groups where I had a student with a birthday on the same day. It was cool.

  • @greta8555
    @greta8555 2 года назад +1932

    can’t believe I clicked on this video thinking it was called the britney paradox

    • @antoniovergotti1895
      @antoniovergotti1895 2 года назад +9

      Same_

    • @javieraossandon2713
      @javieraossandon2713 2 года назад +43

      LMFAOOO I can imagine you being like "why the hell is he putting babies in the table"

    • @rbyln3112
      @rbyln3112 2 года назад +10

      I thought it said “happy birthday paradox” ;-;

    • @Helianthus_
      @Helianthus_ 2 года назад +16

      Oh baby baby, how was he supposed to know that something wasn't right here?

    • @dr.downvote
      @dr.downvote 2 года назад

      Can't blame after seeing the name Greta! Jk, no offense to you, all goes to Greta thunberg lol

  • @MrChriscable
    @MrChriscable 5 месяцев назад

    I used to do this at a weekly pub quiz with about 30 people and most weeks we had matching birthdays and gave them both a prize. It still surprised me every week even though I know it’s maths but it is so unintuitive

  • @clayrester9342
    @clayrester9342 8 месяцев назад

    this makes sense now that i think back to when i was in school... there were always overlapping birthdays.....

  • @hannahturner6629
    @hannahturner6629 3 года назад +1438

    it took me so long to realize the “babies” weren’t popcorn

    • @katongules2346
      @katongules2346 3 года назад +26

      I thought they where teeth

    • @MetrioGaming_
      @MetrioGaming_ 3 года назад +8

      I thought they were dogs

    • @EXA1024_
      @EXA1024_ 3 года назад +8

      @@MetrioGaming_ wΗαt

    • @cjfdnqkn4374
      @cjfdnqkn4374 3 года назад +2

      I thought they were drops of coffee

    • @zooeysmith529
      @zooeysmith529 3 года назад +2

      How did you know what i was thinking?

  • @dominiksipos7836
    @dominiksipos7836 3 года назад +11048

    I'm not really sure that I understand this, but..... Merry Christmas!
    After one year... I still don't understand. Merry Christmas!

    • @vlad_k0o291
      @vlad_k0o291 3 года назад +35

      Happy babys or birthday or holydays...u get the point

    • @maddiem1908
      @maddiem1908 3 года назад +14

      Merry Christmas to you too, Dominik!

    • @TailorJulz
      @TailorJulz 3 года назад +2

      Marry christmas me too

    • @tianna_is_online
      @tianna_is_online 3 года назад +10

      merry chrisler

    • @nc7880
      @nc7880 3 года назад +2

      Merry christmas :)

  • @user-qz3oi9qc2j
    @user-qz3oi9qc2j 5 месяцев назад

    This was once explained in a statistics class. One student just couldn't believe it so the lecturer asked everyone to share their birthday in turns. I think we had gone through only 10 students when it turned out two persons had birthday ON THAT EXACT DAY. This was a literal "and then everyone clapped" moment as, well, everyone did.

  • @golbez3794
    @golbez3794 Год назад +1

    I work at a liquor store. Whenever I ID someone I'm going to write down their birthday. I'll keep writing them down until two match.

    • @minkmiau
      @minkmiau Год назад

      Have you found people already?

  • @unboiledegg5765
    @unboiledegg5765 5 лет назад +2013

    2:50 “Babies.......... erasing babies.......
    Ok that’s not good”
    -Kevin 2018

    • @MaxTheCat-eh5ts
      @MaxTheCat-eh5ts 5 лет назад +2

      Unboiled Egg oof

    • @mechacode8527
      @mechacode8527 5 лет назад +14

      Wow... I have read comments that claim to see a comment quoting the guy in the video in the exact time the guy in the video says it... I thought it was very hard for that to happen, but that has just happened to me with your comment.

    • @KitsuneCentral
      @KitsuneCentral 5 лет назад +14

      Mr. VSauce, I don't feel so good.

    • @gqh007
      @gqh007 5 лет назад +28

      Fetus deletus

    • @GarfieldPhone
      @GarfieldPhone 5 лет назад +9

      Abortion

  • @GK-dp6oy
    @GK-dp6oy 2 года назад +1131

    Are we not gonna talk about how he has 75 miniature plastic babies?

    • @InfinityChances_
      @InfinityChances_ 2 года назад +6

      uhhh

    • @nuraxgaming6601
      @nuraxgaming6601 2 года назад +130

      He's the guy in the math problem

    • @amiehueble1880
      @amiehueble1880 2 года назад +31

      lol, you can get these on amazon, my friend and i actually bought these to hide around out school

    • @ryanwatkins138
      @ryanwatkins138 2 года назад +5

      @@amiehueble1880 haha someone at my school did that too

    • @matthewtepedino3332
      @matthewtepedino3332 2 года назад +18

      he has 100

  • @south_koreaball
    @south_koreaball День назад

    What do you do for a living?
    Hacker: I hack using baby birthday math

  • @fruityskyline2237
    @fruityskyline2237 8 месяцев назад +1

    At the end, I wasn't expecting you to take a candle with the number 2. That is my birthday number and the month when the video was published is also my birthday. I think maybe you could try finding some math probabilities or paradox or whatever you want for those conditions to happen ! LOL !

  • @serenecatweather5694
    @serenecatweather5694 2 года назад +4665

    I can confirm this theory. In my class of 10 people, 1 dude has the EXACT same birthday as I. In another class of mine, of 22 people, someone else shares the same birthday as me too. It’s a miracle !

    • @ssvn7vii
      @ssvn7vii 2 года назад +55

      Well my birthday is New Year’s Eve, so can’t relate.

    • @mattthedestroyer2804
      @mattthedestroyer2804 2 года назад +140

      That's not a scientific confirmation

    • @natetollett5515
      @natetollett5515 2 года назад +61

      Well that actually isn’t backing this. The chances of you sharing your birthday with someone in your class if 10 is still 10/365

    • @Monmon-ve9qp
      @Monmon-ve9qp 2 года назад +18

      that's cool! Our class has 50 students and none of them had the same birthday as me😭😭

    • @leafsculpture
      @leafsculpture 2 года назад

      I met someone from my own school who had the same birthday

  • @CarlaSofieFM
    @CarlaSofieFM 2 года назад +2522

    Him: *pours tiny babies onto table* "Ive got 23 babies"
    Me: "Cool"

  • @zoe127
    @zoe127 9 месяцев назад

    RUclips really showed me this on my recommendations on my birthday

  • @pirimi
    @pirimi 4 месяца назад +1

    I love probabilities and math like that, but when it comes to school math it's like we're arch nemeses

  • @whatcanidooo
    @whatcanidooo 2 года назад +1854

    The fact that so many non-twin siblings share birthdays has always seemed wild to me but now it makes a little more sense

    • @spitfire_saint4428
      @spitfire_saint4428 2 года назад +175

      Nah, their parents just have a "get busy" month. Usually Christmas.

    • @tati-anaroseee4316
      @tati-anaroseee4316 2 года назад +44

      My sister has the same birthday as me but exactly 10 years younger and it confuses tf out of me

    • @anteriax5175
      @anteriax5175 2 года назад +17

      Ive got a lil bro 3 years younger with the same bday. I dont feel special anymore :'(

    • @SuperSkyhorse
      @SuperSkyhorse 2 года назад +16

      @@spitfire_saint4428 or valentine's day

    • @Connarmankeskateboarding
      @Connarmankeskateboarding 2 года назад +10

      My brother was born on February 16th 2010, that’s the same exact date my cousin was born. On top of that my mom and my cousins mom are twins.

  • @JVR10893
    @JVR10893 4 года назад +1129

    “You have the same chance of being born on one of the 365 days in the year”.
    Press F for leap day babies.

    • @hannahharrow8425
      @hannahharrow8425 4 года назад +9

      I'm leap day kid 1996

    • @fluj5170
      @fluj5170 4 года назад +3

      im the party pooper that ruined the 69 like count get rekt

    • @familyali795
      @familyali795 4 года назад +4

      @@hannahharrow8425 lets go twin

    • @eyesonfiresettopanicatthew276
      @eyesonfiresettopanicatthew276 4 года назад +15

      @@hannahharrow8425 so.. Ur six now at the end of the month? grats!!!!

    • @NPW007
      @NPW007 4 года назад +6

      If you are born on the 29th of Feb than you get to choose the date of your birthday is on the 28th of Feb or the 1st of March

  • @ASd-mg5gs
    @ASd-mg5gs 7 месяцев назад

    I really love michael's video, even though i don''t understand almost nothing!