Permutation formula | Probability and combinatorics | Probability and Statistics | Khan Academy

Поділитися
Вставка
  • Опубліковано 25 гру 2024

КОМЕНТАРІ • 369

  • @shapi9861
    @shapi9861 4 роки тому +145

    I need this kind of teacher in class. I usually understand my own math teacher and even get 95 straight grades for the first 3 quarters but then I just don't seem to understand him when probability lesson came. I love math so much that it's such a big deal for me if I don't understand it

    • @ramensguy
      @ramensguy 3 роки тому +3

      I'm exactly in the same situation as you (-__-;)

    • @felixgeorge665
      @felixgeorge665 2 роки тому +2

      What is this the reunion of straight A student's or something

    • @bigdraco7967
      @bigdraco7967 2 роки тому

      @@felixgeorge665 lol

  • @dylannolan7454
    @dylannolan7454 5 років тому +519

    The way he works backwards towards the formula is why he is the best math teacher.

  • @owencave7077
    @owencave7077 6 років тому +575

    Just learned more from a 7 minute video than I would in an hour math class with my easily distracted football coach-teacher and annoying loud kids who can’t shut up

    • @mathsnerdmore7458
      @mathsnerdmore7458 5 років тому +9

      Owen Cave your my twin.

    • @ItsGosho
      @ItsGosho 5 років тому +3

      same

    • @lizhilin8738
      @lizhilin8738 5 років тому +4

      Can’t agree more

    • @lizhilin8738
      @lizhilin8738 5 років тому +2

      Same

    • @kaizen3876
      @kaizen3876 5 років тому +7

      I dont even listen in class , i come home and learn from this. Im way ahead of my class.

  • @ceyceydaaa
    @ceyceydaaa 4 роки тому +54

    Hi, I'm writing from Turkey. Since I discovered Khan Academy, I listen your lessons at least 1 hour a day. There was one main reason at first: to develop my English level and learn some terms. But then I realized that you are telling the reasons of formulas. That's why I wanna thank you. You deserve more followers, everyone MUST know these teacher cause they're awesome!

    • @sevvalrich
      @sevvalrich Рік тому +1

      I'm from Turkey too, glad to see this comment 🥰 I'm studying for my university exam and I'm also improving my English :)

  • @ionloghin2172
    @ionloghin2172 5 років тому +382

    I swear to god, if this was shown in schools on the projector, I honestly think being a math teacher will no longer be a job.

    • @omerozdemir1395
      @omerozdemir1395 5 років тому +7

      LOL AAHAHAHAHAHAH

    • @PhantomAyz
      @PhantomAyz 4 роки тому +12

      Well every teacher has their own way of teaching which could either be better or worse

    • @blank2736
      @blank2736 4 роки тому +3

      there are good teachers too lol not all math teachers are bad

    • @user-og9nl5mt1b
      @user-og9nl5mt1b 3 роки тому

      You want to replace eddie woo with this?

    • @BeastGamerNN
      @BeastGamerNN Рік тому +1

      Totally wrong perspective

  • @laurenking5581
    @laurenking5581 5 років тому +63

    You just took an 1hr 15m lecture and put it into 7.34 minutes. Thank you.

    • @pipe.smoking.modern.cat.
      @pipe.smoking.modern.cat. 7 місяців тому

      7.34 min is equal to 7 min and 20.4 sec. The video is 7 min and 34 sec, not 7 min and 20.4 sec.

  • @JoeBlo2
    @JoeBlo2 9 років тому +41

    I had such difficulty conceptualizing the equation but this video summed it up perfectly and with ease. Thanks again!

  • @ramonaraujo650
    @ramonaraujo650 6 років тому +50

    This guy is so good. Light bulb just turned on!!!

  • @lokeshgoyal9419
    @lokeshgoyal9419 Рік тому +5

    You expained in the way i want, as i also don't like to remember the formulas, but to remember the logic behind it, so that i can generate my formula for my own situations, whenever i need it.
    Great Thanks!

  • @TheTestedTutor
    @TheTestedTutor 5 років тому +73

    My tutoring role model, inspired me to start a channel.

  • @WebDevAnjali
    @WebDevAnjali 2 роки тому +2

    this my first time watching your video and you're my maths crush now. I LOVE YOU.
    I have been learning permutations for so so long n also solved many questions but by sort of memorising the formulas but your explaination made it soooooooooooo easly n understandable like now i'd never need to memorise iy anymore. i can not ever forget it now. you made me love maths again. THANK U SO MUCH.

  • @zinebssakhi1764
    @zinebssakhi1764 2 роки тому +4

    what I like most about Khan's Vids, is that we don't need to memories formulas because we understand them and we discover the logic behind ... Thank you so much

  • @rceby2024
    @rceby2024 11 місяців тому +1

    dude, my confusion is cleared for just a ahort period of time. THANK YOUUU!!

  • @craighennessy3183
    @craighennessy3183 2 роки тому +4

    I have been trying to find a good explanation of the proof of the permutation formula and this is by far the best I have found.

  • @tanmaychavan743
    @tanmaychavan743 Рік тому +3

    Nothing on youtube have explained as best as this. ❤❤❤

  • @IRenataI
    @IRenataI 3 роки тому +6

    Спасибо большое за объяснение, стало понятно!

  • @yujusushi
    @yujusushi Рік тому +1

    Absolute king, makes it so much more easier to understand with the visualization instead of blindly following a formula

  • @Jemmeh
    @Jemmeh 6 років тому +13

    This is so great and clear, thank you so much!

  • @krissp8712
    @krissp8712 4 роки тому +11

    4:09 I liked how he explained how to stop the factorial, and even how to manipulate the factorial as (5-3)! -- that was really helpful!
    But then he kinda threw away that goodwill when he said to reason it out every time! You gotta learn these formulas for the binomial theorem, you can't just sit there in an exam trying to derive it from first principles every time! xD We're not always able to take our time :P

    • @basiliskvenomcandy
      @basiliskvenomcandy Місяць тому

      it's not about always deriving the formulas. I think what he meant was that he likes to know how and why he's doing what he's doing. like he's not just mindlessly using the formulas printed in textbooks.
      If you think about it like that, everytime you understand completely what you're doing from the scratch, it doesn't take a lot of time to kind of derive the formulas in your mind during exams. It takes like 2 seconds to recollect it all. that's how fast your brain can function.

  • @boody_tube
    @boody_tube Рік тому +1

    Man ur way of explaining, ur accent and ur voice is so amazing

  • @apoleyash6852
    @apoleyash6852 3 роки тому +5

    This really helped me a lot! I like how he explained the whole thing. I just subscribed to him after watching this video.

  • @hazeldsouza9568
    @hazeldsouza9568 2 роки тому +3

    My Lord! I've finally understood this concept thanks to you Khan sir! Wish we had YT when we were students!

  • @MineCrafterCity
    @MineCrafterCity Рік тому +2

    You explained this 10x better than my teacher. He made it really complicated and confusing, but if you explain it like this it's way easier to understand.

  • @petemitchell1403
    @petemitchell1403 9 місяців тому

    6 years ago, I came across this gold when i was finding permutations combinations and probability hard to understand. Now I came across this video again for my Probabilty course in university too. Still the best video on the topic. Reminder of a beautiful time gone now😔As Tony Stark said,°Dead for centuries and still taking me back to school°

  • @shriyapandeymishra1898
    @shriyapandeymishra1898 4 роки тому +2

    Khan academy is simply magical.....so very helpful!!

  • @GloriaMaruchu
    @GloriaMaruchu 8 місяців тому

    this is the best explanation i have ever seen, i have been memorizing the formula without understanding the logic behind until today. Thank you.

  • @TuaGlazer
    @TuaGlazer Рік тому +1

    Definitely not procrastinating and cramming rn. Great video

  • @SoftwareDev123
    @SoftwareDev123 2 роки тому +1

    Thank you. You have changed my life. Keep it up.

  • @NudaLuna
    @NudaLuna 8 років тому +167

    I think I am officially in love with Sal Khan.

    • @yomamasofat413
      @yomamasofat413 8 років тому +9

      +NudaLuna me too. This guy is a genius at teaching

    • @Risk1channel
      @Risk1channel 7 років тому +1

      NudaLuna 4th 😅

    • @zes7215
      @zes7215 6 років тому

      Max Tan no such thing as genius at tex or not or good or bad about it, cept u, teach/can teach any by any and any can be perfx. wrg, no such thing as interesx or not or more less, any can be any interesx etc.

    • @edwardliu9325
      @edwardliu9325 6 років тому +1

      Seldom Pooper lmao ikr i couldn't make out anything he was typing

  • @delightedshow7938
    @delightedshow7938 2 роки тому +1

    Thanks a lot for such short & crisp explanation
    Love from Pakistan

  • @Random13Guy
    @Random13Guy 6 місяців тому

    Khan Academy never fails to provide a clear-cut concept. Thank you for this gem.

  • @headglitch4074
    @headglitch4074 3 роки тому +1

    God given talent,
    Perfect interaction even when it's not physically I grabbed all the info possible........wow

  • @JMSobrevilla
    @JMSobrevilla 8 років тому +34

    I looove u so so much. My math teacher is full of formulas and rarely rarely visualizes it. Oh well that's part of life

    • @hossamhamam2900
      @hossamhamam2900 6 років тому

      ^_^ and mine too the same

    • @shapi9861
      @shapi9861 4 роки тому

      Same, I never understand the whole probability lesson because my math teacher never visualize or differentiate combination and permutation

  • @nimrahenna
    @nimrahenna 8 місяців тому +1

    Pure Gold 🥇

  • @ukaszgocek2352
    @ukaszgocek2352 6 днів тому

    Great video and explanation - excellent teaching. I love the reason first, formula second approach.

  • @dennisachesa3358
    @dennisachesa3358 Рік тому

    U made me comprehend whatever looked so difficult in my math's teacher lesson,thanks l can now sit to my exam comfortably

  • @Epeueierhieej
    @Epeueierhieej 4 роки тому

    im going into 6th grade and i never understood permutations and never heard of it. Second time trying to learn this and i got it in 7.34 minutes. ur amazing sal

  • @madsbrdsgaard5315
    @madsbrdsgaard5315 7 років тому +5

    Thank you! Really appreciate your lessons! :)

  • @NathanAndreiBacsa
    @NathanAndreiBacsa 11 місяців тому

    Thank you Khan academy for making this educational video. I now know how to solve permutation problems.

  • @arijitroy005
    @arijitroy005 3 роки тому

    My maths book is filled with formulas... I myself did it this way (just by applying common sense, without using any formula) and showed it to my maths teacher and he was like, "No you can't do this. Do as shown in the book...". God, I hate him. Man knows nothing other than book and formulas. I wish I had a teacher like you. Saw this video after coming from maths tuition btw. Great work...

  • @sunnylefabulous6736
    @sunnylefabulous6736 5 років тому +7

    is it normal to be deeply in love with a youtube channel

  • @theVoid524
    @theVoid524 6 років тому +2

    This helped me so much. Thank you

  • @druebio851
    @druebio851 3 роки тому

    Thank you for this, gonna have this lesson tomorrow and I just realized that I can look at the question and just use my head instead of some complicated formula.

  • @Giankurl
    @Giankurl 11 місяців тому

    This is a very helpful guide on how to understand the formula of permutation, thank you so much!

  • @silverphoenix_1756
    @silverphoenix_1756 2 роки тому

    3:55 And I believe that's the best way to do it.

  • @no_name_magician
    @no_name_magician 6 років тому +3

    Thanks for the concept. I also like to visualize things but there are some obstacles, due to which i am forced to memorize things and i hate memorizing, i am really bad at it.

  • @gracevelasco2167
    @gracevelasco2167 7 років тому +1

    Thanks for the help! my test is tomorrow and this really helped alot

  • @Mohacks
    @Mohacks 2 роки тому

    That's the best explanation of the Permutation formula, also explained it backwards, what a great video

  • @doktah5571
    @doktah5571 6 років тому +2

    i love you Khan-sensei!!

  • @jimmycricket7385
    @jimmycricket7385 Рік тому +1

    Understanding over parrot learning....love it. Well done Khan Academy.

    • @josiahhuang5756
      @josiahhuang5756 Рік тому

      You meant “parent learning,” right?😂😂😂

    • @anshulacc
      @anshulacc Рік тому +1

      @@josiahhuang5756 no he intentionally intended "parrot learning" as it portrays the "mimicking style of learning" that's usually taught in schools....

  • @দূর্বা০০০১

    Cery helpful to understand how the formula came into being, the logic. This ll hrlp students to remember understanding the reasoning instead of memorizing..

  • @cosmos1980
    @cosmos1980 Місяць тому

    This guy is brilliant!

  • @brooklynusa670
    @brooklynusa670 5 місяців тому

    Thank you for clear articulation❤

  • @asura-2467
    @asura-2467 2 роки тому

    I wish i had u as as my math teacher back in my school days

  • @menzimgazi629
    @menzimgazi629 7 років тому +2

    u nailed it
    this will help me in second semester

  • @yerisat9342
    @yerisat9342 7 років тому

    Khan is doing wonders for people trying to learn basic math concepts! I would have never really understood the idea behind the formula had he not "reasoned" it through! thanks Khan

  • @muhtesemzehrad1382
    @muhtesemzehrad1382 6 років тому +2

    I'm from turkey and im watching ur videos 😃

  • @puneetsingh6148
    @puneetsingh6148 3 роки тому +1

    Amazing! Concept cleared

  • @ronniegarcia6410
    @ronniegarcia6410 8 років тому +66

    can you be my math teacher pls

    • @lifelonglearner1863
      @lifelonglearner1863 6 років тому

      Ronnie Garcia sure! Taka taka coaching classes! Come here fast! Timarni village. India

    • @ihumbleyou
      @ihumbleyou 5 років тому +1

      ?

    • @trueverdicts685
      @trueverdicts685 5 років тому +1

      He's everybody's maths teacher by making videos online ;)

    • @ihumbleyou
      @ihumbleyou 5 років тому

      @@trueverdicts685 lol

  • @DonNobyel
    @DonNobyel 6 років тому +27

    maybe person B like to sit in one chair only - Haha Dr. Sheldon Cooper, is that you?

  • @syahirahfirzanah
    @syahirahfirzanah 2 місяці тому

    GREAT EXPLANATIONN

  • @luisseisabelb.torion6186
    @luisseisabelb.torion6186 3 роки тому +1

    i just cant concentrate. his voice is so good and mesmerizing

  • @remotestuff8721
    @remotestuff8721 3 роки тому

    This channel saved me a lot in my studies

  • @namnam7234
    @namnam7234 5 років тому

    he teaches waaaay better than any of my math teachers

  • @ziziphobusakwe1704
    @ziziphobusakwe1704 4 роки тому

    You're literally the best!!!

  • @gasserhegazy1267
    @gasserhegazy1267 Рік тому

    thank you so much, I didn't understand it in class but this is gold.

  • @MrGiuse72
    @MrGiuse72 Рік тому

    BEST EXPLAINATION !!

  • @SathvickSatish
    @SathvickSatish 8 років тому +9

    Thank you Sal!

  • @paytonclark7501
    @paytonclark7501 7 років тому +24

    “Seaten” I’m dead 😂😂

  • @xinchen9832
    @xinchen9832 3 місяці тому

    He explained the logic behind the formula.

  • @Sara-lilia
    @Sara-lilia 2 роки тому

    Thank u 💓really helpful

  • @i_am_gods_child
    @i_am_gods_child 3 роки тому

    i got so scared when he quickly went 'so this mean the formula' but then *phew* when he said he thinks its better to go through it by logic. thankyou so much for the videooo!!!!!

  • @boyshanks
    @boyshanks 6 місяців тому +1

    Without a calculator - is there any quick way or hack to calculate a longer factorial? Like 7!? or 23! ? Thanks

  • @laurengrondman
    @laurengrondman Рік тому

    Super helpful! Thank you

  • @PreetiYadav-zs9db
    @PreetiYadav-zs9db 3 роки тому

    Thankyou sir 🙏🏼🙏🏼

  • @richardadamwais9734
    @richardadamwais9734 4 роки тому

    thanks your explaination it is such get chance during difficult time of covid pandemic

  • @adengoher4343
    @adengoher4343 3 роки тому

    Thank you for this video!

  • @iloveblackpink3106
    @iloveblackpink3106 2 роки тому

    thank you for this 😭💓

  • @Fernandosilva-qq7ki
    @Fernandosilva-qq7ki 6 років тому +1

    Very helpful thank you

  • @cleopatramak
    @cleopatramak 2 роки тому

    Thank you for explaining so well

  • @graysonhaemmerle7205
    @graysonhaemmerle7205 4 роки тому +1

    Okay I love his handwriting like wha...

  • @PrasannaKumar-zx7gr
    @PrasannaKumar-zx7gr 6 років тому

    thank you .what I hope you you told and impresed me...keep on uploading more and more logical videos..my teacher always told me to mugup the formula.

  • @diivhupng1420
    @diivhupng1420 2 роки тому

    I like your explanation. If I would rate it 100% perfect🥰

  • @jeffreydwightryanriley8308
    @jeffreydwightryanriley8308 2 роки тому

    I see you're using the absolute value.

  • @iconbylvergara6188
    @iconbylvergara6188 7 років тому +1

    I also don't like formulas. This is the best! TY

  • @joe_matt
    @joe_matt 5 років тому +1

    What a Legend!

  • @adilmuhammad6078
    @adilmuhammad6078 3 роки тому

    Thank you very much 🙏

  • @Syntaxxed
    @Syntaxxed 11 місяців тому

    and in my school we have: variation, permutation (p=n), combination and then repetition variation, repetition permutation and repetition combination :p

  • @wise_fool
    @wise_fool 7 місяців тому

    you rationalized & were able to see the direct logic of it not just symbols cuz you're smart, I'm stupid & in spite of your explanation which sounds logical am still not catching the logic without conflating it with something else,

  • @kartheyansivalingam7927
    @kartheyansivalingam7927 Рік тому

    If you want to logically work through the question where the number of chairs is more than the number of people. Let's say 10 chairs and 5 people. A useful tip is to reverse the "natural" way you will think about this, i.e. instead of counting how many people left to sit on the next chair and so on; we instead count how many chairs left for the next person to sit on. So for the 1st person there are 10 chairs, for the 2nd person there are 9 chairs,..., for the 5th (last) person there are 6 chairs left. So ans: 10x9x8x6

  • @ak_gamer3621
    @ak_gamer3621 3 роки тому

    Thanks sir your made understand it very well

  • @vt6382
    @vt6382 4 роки тому

    Very helpful! Thanks so much!

  • @MI-49
    @MI-49 4 роки тому

    best way of explaining things...excellent

  • @abchannel3347
    @abchannel3347 4 роки тому

    What a good teacher !

  • @qalanjo1989
    @qalanjo1989 Рік тому

    awesome, you are an amazing teacher!

  • @dixiemerchant1052
    @dixiemerchant1052 2 роки тому

    That was really good (better than my class video!)

  • @user-gp8fr1nd3w
    @user-gp8fr1nd3w 4 роки тому

    THANK YOU THANK YOU THANK YOU.

  • @DaudaJalloh-ir5bv
    @DaudaJalloh-ir5bv 10 місяців тому

    Absolutely amazing

  • @trevorgreenough6141
    @trevorgreenough6141 2 роки тому

    Serious question related to this problem: what instead, those 5 people had 2 items each, what would the permutations of the items be, if 2 people swapped an item?

  • @1975coucou
    @1975coucou Рік тому

    great video! tysm!