#DidYouKnow: Number of permutations of n different things taken all at a time, when m specified things never come together is n! - m! x (n - m + 1)!. ✅To access all videos related to Permutations and Combinations, enroll in our full course now: infinitylearn.com/cbse-fullcourse?UA-cam&DME&UHONj0 To watch more Permutations and Combinations videos, click here: bit.ly/PermutationsCombinationsVideos_DMYT
I)What if the 5 girls sit together out of 11students? II)And what the 5 girls sit in a specified oder? III)AND what the 5 girls sit together in a specified oder
5 years ago was the first time I watched this video, I was preparing for GRE and it had hundreds of views. Now I passed by accident while preparing for Ph.D. entrance exam and this video has hundreds of thousands of views. Thank you Don't Memorise))
omg I finally understood the "why"!! ... I struggled with this for so long and now its so clear. you lady are the best teacher on this topic EVER. thanks a lot
At first, I was really confused when I saw the video, the part when you arranged the 10 boys to be precise. So I watched the last two videos again. Then I understood the how you were going about the logical way to find the answer. You basically just turned the "selecting 3 boys out of the 10" part into the anagram type. When we are asked to select 3 boys out of 10, we are only fixated on the "selecting 3 boys" part, but forget to think about the other 7. And you used that to explain the logic to find the answer. I think that's brilliant !!!! Basically, the 10 boys are being arranged in a line and then the first 3 are selected (That's what's shown as an example in this video). This is 1 way of selecting 3 boys out 10. And then you follow what was taught in the last video. If all the 10 items are different then there are 10! ways in which they can be filled. But here, 3 are similar to each other and the rest 7 are similar to each other (on the basis of being selected or not). Therefore, 10! is divided by 3! and 7! (which means that 3! & 7! are being multiplied in the denominator with 10! in the numerator). In a way, one can say that combinations are permutations divided by the (number of similar items)! . Mathematically may be, it would be wrong to say that but that's what's happened here, a combinations' problem has been solved using the basics of permutations. @don'tmemorise How much of what I have said here is actually true?
Thanks a lot for explaining the logic behind it bro. I was confused even after watching the video for several times , But your written explanation made me clear. Thank you.
If somebody has doubts on why not simply put 10*9*8 for boys and 8*7*6 for girls, Then the explanation from my side is 10*9*8 gives the total possible ways that 3boys can be selected from 10 if the order of the boys don't matter (Steve Rogers , Bucky , falcon is same as falcon,bucky ,Steve and so on) . The 10*9*8 gives that there are 720 ways from which 3 boys can be selected from a group of 10boys . BUT THE PROBLEM IS ......ok wait .... Just for the moment if You group the result(720 ways) irrespective of their arrangement i.e (steve Rogers , bucky , falcon is same as falcon,bucky ,Steve and so on are considered as a SINGLE UNIQUE group) You may see each group has 6 participants (Eg : group 1 = abc,acb,bac,bca,cab,cba) or in other Words for every 6ways in total 720 ways there is only ONE - UNIQUE - TRUE fux*ing combination... here 6 is 3! and 720 has 120 equal 6 in it(720/6 = 120).....10*9*8 / 3! can also be the Right answer if 3 boys taken from 10 for a superHero team ..... it is same as "MOOC " and now I understand both "Mooc" and this problem after after 10+ unsuccessful attempts
This makes a lot of sense, thank you for this. I immediately went to 10*9*8 and was wondering why she went straight to factorials. Order not mattering is huge on this since you're right, abc is no different than bac or cab in this problem.
@@tufailabbasmaknojia6944 She has sound knowledge of the subject. She is an excellent teacher. Albert Einstein once said: "If you cannot explain it simply, it means you do not understand it well enough."
im not in the uk or India like most of the students commenting but i am in south africa and doing a math degree,this sure helped a lot. Thank you very much
Love from india Thank you so much ma'am thanks a lot for it ... You made my day easy and my night peaceful coz i m so worried about my pnc doubt and you solved it all God bless you mam ... Thank you so much...
Thank you so much Patrick! Means a lot! By the way, we don't upload all our videos on UA-cam. To get access to all PnC videos for free, visit our website here: dontmemorise.com/course/view.php?id=92 Enjoy :)
Hey Patrick, many people find Mixtures and Alligations difficult to understand. Here's a playlist that makes it sooper easy: dontmemorise.com/course/view.php?id=132 Also, if you wish to give your brain a quick work out, here's a series of WarpMath videos: dontmemorise.com/course/view.php?id=135 Happy Learning :)
You're most welcome Akshaya. We are really happy to hear that it was helpful for you. We are glad that you understood the concept. You motivate us to do better. Keep watching our videos : )
For anyone this confused, I'll try to break it down. If you watched the anagram video, you would of seen the example of excessive. How many ways can excessive be rearranged. The total number of letters is 9 (Some letters are the same, but we count them anyway) So we do 9! How many Letters are the same: E repeats 3 times. So 3! S Repeats 2 times. So 2! Remember, if something is the same, divide the total factorial by the thing that is the same factorial so 9!/3!2! But what does that have to do with the question in this video?....Well, a lot actually For the boys, we have a total of 10. So 10! 3 Are selected, 7 aren't. S S S NS NS NS NS NS NS NS The 3 S's are the same, and 7 NS's are also the same. Just think of the as letters. What do we do? Well remember, if anything is the same, divide the total factorial by the the thing that is the same factorial S repeats 3 times, so 3! NS repeats 7 times, so 7! So 10!/7!3! Alrighty, we've done the boys. What about the girls? Well, it's the exact same thing. Took me hours to understand this, so don't worry if you had trouble. You'll get there
Correct me If am wrong.. Lets see the case of boys in the problem. There are three seats in the event for the selected boys out of 10 boys. ___ ___ ___ In that case , The first seat can be filled by 10 boys The second seat can be filled by 9 boys The third seat can be filled by 8 boys. Total number of ways for the boys to sit in the seats can be 10 * 9 * 8 = 720 which is also the answer for 10!/(3! * 7!). Any advises will be appreciated. Thanks in advance.
Hi, thanks for the awesome explaination.But I have a doubt with the first example.I think the answer is right, but the perspective isn't because if we classify all the boys/girls as selected and not selected we will end up selecting all the 10 things.Consider the word 'peep' it has items of two types, similar to that of the video, 4! is the total arrangements considering that all the items are distinct.We divide it by 2! twice because there are 2 p's and 2 e's.The answer will be 4!/(2!*2!).Now this consists of all the four letter anagrams like pepe,peep,ppee.Since, the same logic is applied here 10!/(3!*7!) will contain all the 10 item combinations like S S NS S NS NS NS NS NS NS. Please clearify this to me. I mean no disrespect and I appreciate the effort put into making this series.Please reply as fast as possible.
In the example of choosing 3 students from 10 students, the number of distinguished groups of selected students = the number of distinctive groups for unselected students because each distinct group of selected students corresponds to a distinct group of unselected students that comes with it only, for example, if the ten students are (Sarah - Ahmed - Laila - Youssef - Fatima - Ali - Zainab - Jamil - Nour - Hisham), then one of the distinctive groups of the selected students when choosing 3 students from 10 students is (Fatima - Youssef - Zainab) when this possibility occurs with him in a way It is inevitable not to choose (Sarah - Ahmed - Laila - Ali - Jamil - Nour - Hisham) and therefore we consider the two distinct groups as one possibility because they must occur together if the total number of possibilities = the number of distinctive groups for selected students = the number of distinct groups for unchosen students, but the problem in the example that I mentioned can be arranged (Fatima - Youssef - Zainab) with 3! Of the ways, we can say (Yusuf - Fatima - Zainab) or (Zainab - Fatima - Yusuf) and other ways, as well as (Sarah - Ahmed - Laila - Ali - Jamil - Nour - Hisham) can be arranged with 7! Of the ways, we can say (Ahmed - Sarah - Laila - Ali - Jamil - Nour - Hisham) or (Ahmed - Sarah - Hisham - Ali - Jameel - Nour - Layla) and other ways and each method of arranging the selected students is calculated with all the methods of arranging the unchosen students, so each possibility has one number 3!*7! One of the ways to arrange it, but I'm not interested in the order, I just want to know the number of possibilities and therefore divide all possible rankings, which are 10! On 7!*3! And it's the number of ways to arrange each probability. I'm sorry my explanation isn't clear, but it took me two days to understand this issue. Uh, a lot of wasted time, but finally I got it.
Hi Ali, yes it's better you watch our videos right from the start as the concepts are linked :) Here's the link: ua-cam.com/video/0NAASclUm4k/v-deo.html
Thank you so much Mira! Do subscribe to our UA-cam channel by clicking here: bit.ly/DontMemoriseUA-cam It'll keep you updated about our latest uploads :)
If there is the case of color balls Question: A bag contains 6 red and 4 yellow balls. 4 are picked at random. What is the probability that 3 are red and one is yellow?
I have a question. Why can't we use the same process that we used from the forming numbers part where we only need to put slots and then count the ways of how they can be arranged?
Actually, if we picked 10 boys out of 10 we would have one way, and if we picked one boy out of 10 we would have 10 ways, so boys do differ here, since we selected 3 out of 10, we're only interested in the "uniqueness" of the combination. otherwise if boys weren't different, there would be only 1 way to pick 3 boys out of 10 which is BBB (B for boy), but if we numbered them: B1,B2,B3..B10 we would have sense of why we got 120 ways just to select boys. we could get B1,B2,B3. in another unique set: B2,B3,B4 and so.. Correct me if i'm wrong.
No! we have to divide 10! by (3! * 7!). EAXPLAINATION -> Since each boy is unique, we can assign each boy with a unique Number(say 0,1,2,3.....9). Then if we select 3 boys out of 10 we can have (boy numbered) 1,2,3 and 2,1,3 both in the 10!, but both the cases are same sice the ordering doesn't matter. Therefore, 10! has all these cases, and we divide by 3! too.
ma'am , I didn't get the part in which you named selected as S and not selected as NS and again divided them by 3! and 7!.....similarly for the girls as well ....
+Zeel Patel , yes it's easier. But for students that do not understand PnC, we have given them a very logical approach in this video. We have covered the formulae at a later stage.
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#DidYouKnow:
Number of permutations of n different things taken all at a time, when m specified things never come together is n! - m! x (n - m + 1)!.
✅To access all videos related to Permutations and Combinations, enroll in our full course now:
infinitylearn.com/cbse-fullcourse?UA-cam&DME&UHONj0
To watch more Permutations and Combinations videos, click here: bit.ly/PermutationsCombinationsVideos_DMYT
OMG 😱 , thank you so much awesome explanation , from point to point🙏🙏🙏🙏
I won't memorise 😉😁
I)What if the 5 girls sit together out of 11students?
II)And what the 5 girls sit in a specified oder?
III)AND what the 5 girls sit together in a specified oder
Please reply as early as possible
5 years ago was the first time I watched this video, I was preparing for GRE and it had hundreds of views. Now I passed by accident while preparing for Ph.D. entrance exam and this video has hundreds of thousands of views. Thank you Don't Memorise))
🔥
omg I finally understood the "why"!! ... I struggled with this for so long and now its so clear. you lady are the best teacher on this topic EVER. thanks a lot
At first, I was really confused when I saw the video, the part when you arranged the 10 boys to be precise. So I watched the last two videos again. Then I understood the how you were going about the logical way to find the answer. You basically just turned the "selecting 3 boys out of the 10" part into the anagram type. When we are asked to select 3 boys out of 10, we are only fixated on the "selecting 3 boys" part, but forget to think about the other 7. And you used that to explain the logic to find the answer. I think that's brilliant !!!!
Basically, the 10 boys are being arranged in a line and then the first 3 are selected (That's what's shown as an example in this video). This is 1 way of selecting 3 boys out 10. And then you follow what was taught in the last video. If all the 10 items are different then there are 10! ways in which they can be filled. But here, 3 are similar to each other and the rest 7 are similar to each other (on the basis of being selected or not). Therefore, 10! is divided by 3! and 7! (which means that 3! & 7! are being multiplied in the denominator with 10! in the numerator).
In a way, one can say that combinations are permutations divided by the (number of similar items)! . Mathematically may be, it would be wrong to say that but that's what's happened here, a combinations' problem has been solved using the basics of permutations.
@don'tmemorise How much of what I have said here is actually true?
👍👍👍
Thanks for explaining ❤️❤️
Thanks a lot for explaining the logic behind it bro. I was confused even after watching the video for several times , But your written explanation made me clear. Thank you.
Thankyou for your explanation
This is the best series I've ever watched. I've literally paused this video to write this comment. It cleared most of my doubts regarding P&C.
If somebody has doubts on why not simply put 10*9*8 for boys and 8*7*6 for girls, Then the explanation from my side is 10*9*8 gives the total possible ways that 3boys can be selected from 10 if the order of the boys don't matter (Steve Rogers , Bucky , falcon is same as falcon,bucky ,Steve and so on) . The 10*9*8 gives that there are 720 ways from which 3 boys can be selected from a group of 10boys . BUT THE PROBLEM IS ......ok wait ....
Just for the moment if You group the result(720 ways) irrespective of their arrangement i.e (steve Rogers , bucky , falcon is same as falcon,bucky ,Steve and so on are considered as a SINGLE UNIQUE group)
You may see each group has 6 participants (Eg : group 1 = abc,acb,bac,bca,cab,cba) or in other Words for every 6ways in total 720 ways there is only ONE - UNIQUE - TRUE fux*ing combination... here 6 is 3! and 720 has 120 equal 6 in it(720/6 = 120).....10*9*8 / 3! can also be the Right answer if 3 boys taken from 10 for a superHero team ..... it is same as "MOOC " and now I understand both "Mooc" and this problem after after 10+ unsuccessful attempts
Thanks
This makes a lot of sense, thank you for this. I immediately went to 10*9*8 and was wondering why she went straight to factorials. Order not mattering is huge on this since you're right, abc is no different than bac or cab in this problem.
You save my life.Thank you brother ❤❤❤
I was literally thinking bout it!! You made this so easy. Thanks a lot. Made my day.
I like how you give the origin of the formula. I just did a few combinations examples on my channel!
I subbed!! :D
Thank you for your humility to appreciate your competitors.
Simple, neat and clear explanation! Thanks!
Thank you for your comment Radhika :)
FINALLY! This cleared all my doubts, it was like a 'eureka' moment after countless videos. Thank you so much!
"We cannot select boys from the group of girls or vice versa" Finally, Someone explains it logicallly lol
ohhhhhh.mannnn,i mean womaaaan thankx for this logical explanition ..............
@@tufailabbasmaknojia6944 She has sound knowledge of the subject. She is an excellent teacher. Albert Einstein once said: "If you cannot explain it simply, it means you do not understand it well enough."
@@mthobelinathanheshu8423 you are right
Hamari choriya choro se kam h ke
2022 is a different time...
Our teaching is absolutely outstanding 😊
easy way to understand Permutation & Combination ..Expecting a lot of videos !!!
Hi Muradar, here's the entire list for you, for free: dontmemorise.com/course/view.php?id=92
Let us know if you've viewed all these videos :)
Wow! Really love these explanations. Simple and easy to digest. Starting to get a better understanding of permutations and combinations.
Awesome! :)
im not in the uk or India like most of the students commenting but i am in south africa and doing a math degree,this sure helped a lot. Thank you very much
You guys are like lee chong wei(badminton legend) making it look so easyyyyy
The best explanation, ever...including graphically.
you are simply amazing. god bless you.
Thank you so much Rana! Don't forget to register on our website here: bit.ly/DontMemoriseRegister
Happy Learning :)
#DontMemorise
Superb presentation by all standards!!.
Many of our maths teachers do not know the concept this way.
Thank you very much for the appreciation and for watching.
To view more videos for free, register on our website: bit.ly/DontMemoriseRegister :)
The best playlist/video series on the topic.
Glad you liked it!
Please subscribe to our channel: bit.ly/DontMemoriseUA-cam
Happy Learning :)
I like how you explain every single one of your videos, this was was a little bit more confusing
Love from india
Thank you so much ma'am thanks a lot for it ... You made my day easy and my night peaceful coz i m so worried about my pnc doubt and you solved it all
God bless you mam ... Thank you so much...
she's not a ma'am , its a computer generated voice...lol me too from India
Abe jaana laude
@@tufailabbasmaknojia6944 no, it's not
@@tufailabbasmaknojia6944there is a video in which she revealed her face
Best video on a single topic ever.
Love you guys,😍😍
You are absolutely great. I wish I had a math teacher of your caliber
Thank you so much Patrick! Means a lot! By the way, we don't upload all our videos on UA-cam. To get access to all PnC videos for free, visit our website here: dontmemorise.com/course/view.php?id=92
Enjoy :)
Thanks for your hints. I viewed all of them (with gusto) this morning. Do you have more? Any other interesting link?RegardsP Tawil
Hey Patrick, many people find Mixtures and Alligations difficult to understand. Here's a playlist that makes it sooper easy: dontmemorise.com/course/view.php?id=132
Also, if you wish to give your brain a quick work out, here's a series of WarpMath videos: dontmemorise.com/course/view.php?id=135
Happy Learning :)
You know what I really don't like this horrible chapter(Mixture and Allegation)
thats what i was looing for, internet is such confusing place
It is very understandable
Thank you for helping me
You're most welcome Akshaya. We are really happy to hear that it was helpful for you. We are glad that you understood the concept. You motivate us to do better. Keep watching our videos : )
I think this videos can useful for my jee mains exam 2020
I Love your videos with logic ad.
It's helps me to built complete understanding.
For anyone this confused, I'll try to break it down.
If you watched the anagram video, you would of seen the example of excessive.
How many ways can excessive be rearranged.
The total number of letters is 9 (Some letters are the same, but we count them anyway) So we do 9!
How many Letters are the same:
E repeats 3 times. So 3!
S Repeats 2 times. So 2!
Remember, if something is the same, divide the total factorial by the thing that is the same factorial
so 9!/3!2!
But what does that have to do with the question in this video?....Well, a lot actually
For the boys, we have a total of 10. So 10!
3 Are selected, 7 aren't.
S S S
NS NS NS NS NS NS NS
The 3 S's are the same, and 7 NS's are also the same. Just think of the as letters. What do we do?
Well remember, if anything is the same, divide the total factorial by the the thing that is the same factorial
S repeats 3 times, so 3!
NS repeats 7 times, so 7!
So 10!/7!3!
Alrighty, we've done the boys. What about the girls? Well, it's the exact same thing. Took me hours to understand this, so don't worry if you had trouble. You'll get there
Thanks a lot, for up to the point information about this chapter.
so clear explanation!
thank u very much for providing these videos , they were very helpfull ,hope u provide more videos
+sanal babu , thank you for your feedback. Yes we will continue to add more videos on our youtube channel as well as on our website DontMemorise.com
You are so good at explaining!! Keep it up!
Thank you very much dear! I think this is the explanation of permutation and combination at all!
You're welcome! Happy Learning :)
I like this chanel very much as its easy to understand
Excellent way of teaching maam👌👍
Thank you so much for your appreciation. We are glad that you understood the concept. For more videos, please visit our website - dontmemorise.com/
Wow I am actually thinking of joining of your premium membership. It's really great. I will very soon.
Great great 👍 the way u tell the logic.
But please explain the logic of combination more clearly.
Why can't we use the counting method for this? I had done [(10x9x8) x (8x7x6)]. What is logically wrong in this method?
really helpful... thank u soo much...
+Jayant Vashisth , you are welcome :)
Thank you!
Tq soooooo much ♥️i can't explain u how much it is helpful for me
Great explaination of the concepts
BEST CHANNEL EVER!
Very good teaching skills
I like ur teaching
Thank you so much mam... u made
it is sooooooo easyyy.........thanku :)
Wow..!!
nicely explained. seen whole playlist
Thanks
+Jaydeep Meda , thank you. Make sure you see all the videos of Permutations and Combinations on our website:
dontmemorise.com/course/view.php?id=92
Please post some videos for data interpretation
Omg thanks a lot!!!
Thank you
Thank you for your explaining. It's great
You're welcome Bader. Please register on our website to get access to ALL videos: bit.ly/DontMemoriseRegister
#DontMemorise
Correct me If am wrong..
Lets see the case of boys in the problem.
There are three seats in the event for the selected boys out of 10 boys.
___ ___ ___
In that case ,
The first seat can be filled by 10 boys
The second seat can be filled by 9 boys
The third seat can be filled by 8 boys.
Total number of ways for the boys to sit in the seats can be 10 * 9 * 8 = 720 which is also the answer for 10!/(3! * 7!).
Any advises will be appreciated.
Thanks in advance.
THANK YOU SOOO MUCH
Very helpful.!
Thank you so much.
Happy Learning :)
Hi, thanks for the awesome explaination.But I have a doubt with the first example.I think the answer is right, but the
perspective isn't because if we classify all the boys/girls as selected and not selected we will end up selecting all the 10 things.Consider the word 'peep' it has items of two types, similar to that of the video, 4! is the total arrangements considering that all the items are distinct.We divide it by 2! twice because there are 2 p's and 2 e's.The answer will be 4!/(2!*2!).Now this consists of all the four letter anagrams like pepe,peep,ppee.Since, the same logic is applied here 10!/(3!*7!) will contain all the 10 item combinations like S S NS S NS NS NS NS NS NS.
Please clearify this to me.
I mean no disrespect and I appreciate the effort put into making this series.Please reply as fast as possible.
Did you get the answer now?
Ur are just Awesome
this is amazing ❤
+Michelle Rodrigues , yay, thank you :)
helpful !!!
Awesome
You are geunius
thanks
+Rashmikiran Pandit , you are welcome. Keep watching and keep learning :)
thanks a lot
I love your videos ! keep doing ;-)
In the example of choosing 3 students from 10 students, the number of distinguished groups of selected students = the number of distinctive groups for unselected students because each distinct group of selected students corresponds to a distinct group of unselected students that comes with it only, for example, if the ten students are (Sarah - Ahmed - Laila - Youssef - Fatima - Ali - Zainab - Jamil - Nour - Hisham), then one of the distinctive groups of the selected students when choosing 3 students from 10 students is (Fatima - Youssef - Zainab) when this possibility occurs with him in a way It is inevitable not to choose (Sarah - Ahmed - Laila - Ali - Jamil - Nour - Hisham) and therefore we consider the two distinct groups as one possibility because they must occur together if the total number of possibilities = the number of distinctive groups for selected students = the number of distinct groups for unchosen students, but the problem in the example that I mentioned can be arranged (Fatima - Youssef - Zainab) with 3! Of the ways, we can say (Yusuf - Fatima - Zainab) or (Zainab - Fatima - Yusuf) and other ways, as well as (Sarah - Ahmed - Laila - Ali - Jamil - Nour - Hisham) can be arranged with 7! Of the ways, we can say (Ahmed - Sarah - Laila - Ali - Jamil - Nour - Hisham) or (Ahmed - Sarah - Hisham - Ali - Jameel - Nour - Layla) and other ways and each method of arranging the selected students is calculated with all the methods of arranging the unchosen students, so each possibility has one number 3!*7! One of the ways to arrange it, but I'm not interested in the order, I just want to know the number of possibilities and therefore divide all possible rankings, which are 10! On 7!*3! And it's the number of ways to arrange each probability. I'm sorry my explanation isn't clear, but it took me two days to understand this issue. Uh, a lot of wasted time, but finally I got it.
Your explanation is good but still I assume I am missing something; I may have to watch all your videos.
Hi Ali, yes it's better you watch our videos right from the start as the concepts are linked :)
Here's the link: ua-cam.com/video/0NAASclUm4k/v-deo.html
superb...easy to understand
Thank you so much Mira! Do subscribe to our UA-cam channel by clicking here: bit.ly/DontMemoriseUA-cam
It'll keep you updated about our latest uploads :)
Very good
Nice video... The videos are really cool. What are you using to animate these videos ?
underrated for a reason
very nice tutorial
Cool 😎
If there is the case of color balls
Question: A bag contains 6 red and 4 yellow balls. 4 are picked at random. What is the probability that 3 are red and one is yellow?
thank you for hard working and explain in a easiest way.
Awesome 👍
You have mentioned in before videos that, and =multiplication, or= addition but here have done vice versa kindly explain :)
I have a question. Why can't we use the same process that we used from the forming numbers part where we only need to put slots and then count the ways of how they can be arranged?
Yup....I got...it...................
Glad to hear that :)
I loved the explanation. Thank you,
I need not memorize now, it's already in the brain
or simply do 10C3*8C3!
Why you relate the above example with anagram as anagram is about arranging letters and here we are selecting things. Would you please elaborate this?
ur best
Actually, if we picked 10 boys out of 10 we would have one way, and if we picked one boy out of 10 we would have 10 ways, so boys do differ here, since we selected 3 out of 10, we're only interested in the "uniqueness" of the combination. otherwise if boys weren't different, there would be only 1 way to pick 3 boys out of 10 which is BBB (B for boy), but if we numbered them: B1,B2,B3..B10 we would have sense of why we got 120 ways just to select boys. we could get B1,B2,B3. in another unique set: B2,B3,B4 and so..
Correct me if i'm wrong.
Mast tha
3:08 We do not multiply 3! by 7! Okay. The answer will be incorrect. We just divide 10! on 7!
No! we have to divide 10! by (3! * 7!). EAXPLAINATION -> Since each boy is unique, we can assign each boy with a unique Number(say 0,1,2,3.....9). Then if we select 3 boys out of 10 we can have (boy numbered) 1,2,3 and 2,1,3 both in the 10!, but both the cases are same sice the ordering doesn't matter. Therefore, 10! has all these cases, and we divide by 3! too.
ma'am , I didn't get the part in which you named selected as S and not selected as NS and again divided them by 3! and 7!.....similarly for the girls as well ....
10 factorial will include all the possibilities.. What does this mean
Actually easy way to sole it is 10C3*8C3=6720.thanks
+Zeel Patel , yes it's easier. But for students that do not understand PnC, we have given them a very logical approach in this video. We have covered the formulae at a later stage.
Ya its good
+Zeel Patel can u explain it in detail pls
thank u
Mam what if there is some obstacles are there then which should we select
Can i use this for 3 DIGIT LOTTERY GAMES??
I don't get it. Why it can't be 10*9*8 for selection of 3 boys out of 10?
As order of selection didnt matter i think you should have add in the last rather then multiply plz clear my doubt
Are they to be repeated?
Nice
Thank you so much.
Happy Learning :)
Why do we multiply for AND but add for OR !(Golden rule🤔)
please say about ^ * probability
Here you go: ua-cam.com/video/TseGryr1JdE/v-deo.html
Happy Learning :)
I understand all the previous videos clearly but not this one...why 10! is divided by 3! And 7! ? Anyone?? Please
Why don't you use combination in this case
What is the editing app that is being used and is the voice real or AI?
What is the logic of multipling 3 boys and 3 girls.