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whoever did not understand this read below let me ask you a question, if you are sitting on any of the 6 chairs arranged in circular, which particular chair are you sitting on most important in this is the word "ways" lets understand what is meant by "ways" one person wants to seat in a chair among six chairs arranged in straight line Q:what are different ways to do so? way 1: SNNNNN //he is sitting on 1st chair way 2: NSNNNN //he is sitting on 2nd chair way 3: NNSNNN //he is sitting on 3rd chair way 4: NNNSNN //he is sitting on 4th chair way 5: NNNNSN //he is sitting on 5th chair way 6: NNNNNS //he is sitting on 6th chair Ans: so there are 6 different ways he can sit on a chair. now when it comes to circular arrangement of chair what are different ways a person can seat on a chair? way 1: SNNNNN /he is sitting on 1st chair way 2: SNNNNN /he is sitting on 1st chair way 3: SNNNNN /he is sitting on 1st chair way 4: SNNNNN /he is sitting on 1st chair way 5: SNNNNN /he is sitting on 1st chair way 6: SNNNNN /he is sitting on 1st chair confused right, circle does not have a starting point,the thing is whenever that person chooses a chair and seats on it,that particular chair itself is the first chair thats why its always going to be "SNNNNN" which is the only one "unique" way that he can sit. ans: one way conclusion: in linear arrangement of chairs whenever a person sits on a particular chair his chair is being referenced from the first chair eg. he is sitting on 3rd chair or he is siting on 5th chair this way we have 6 different ways # but in circular arrangement whichever chair he sits on is the first chair itself bcz there is no start point in circle for reference to say that he is sitting on 3rd chair or 4th chair and so on.
Poor explanation seriously!! Why 1st person sits in 1 way when it has 6 choices? No logic!! Lemme make u understand the reason. Consider 3 men ( a,b,c)... How they can be seated in a circular table? 3! (No, Lmme show you those arrangements and why not 3!) 1) b a. c 2) a b. c 3) b c. a.
@@shaguntripathi2554 I think I have answer for ur question... It is different in clockwise and anticlockwise.. Cuz if u seat facing towards centre and if u seat facing outside the centre... Then there is difference in both scenarios...read again
@@gauravaggarwal2392 bruh we are talking about arrangements and not about facing or not facing centre. I made an extra easy proof that is a lot easier than this video!!! Your welcome if you got that! And i never asked a question
@@shaguntripathi2554 lemme ask u something.. What will u see in clockwise and anticlockwise direction? Are the both views same? I guess no ryt.. So when u see in clockwise and anticlockwise ur facing towards centre in one case and in outside the circle in other case ...that's what I meant above...
That is such a mind blowing explanation. I cannot describe in words how to thank you; because words like "Thank you" won't be ever enough for such a valuable service you are giving to million of students like us. May you live long healthy and prosperously. ❤️😇
These videos(specially 15 videos in this channel) are best way to learn in depth understanding of basics of permutation and combination. Don't Memorise has done commendable job in explaining from scratch .
This is the math I like, thoroughly explaining it, not like bombarding us with so many different formulas and not even explaining it. THANK YOU SO MUCH♥️♥️♥️
The statement you provided is quite thought-provoking. It brings to light the alarming reality of how easily videos influence one. It's a reminder that we should always be mindful of the information we consume and seek multiple sources to ensure a well-rounded perspective. It solved all my doubts Thanks a lot😊♥
It's amazing to me how much more helpful these videos are than the review materials I got that are produced by a top-tier university in my country. Thanks so much, and thank you for making them free. :)
it is just amazing i am so thankful cause i have to explain this lesson to my students and i had no idea how to intoduce it but now :) you video was helpful so thank youu so much
Thank you so much ma'am! This is the best video I have ever seen! To the point answers with total logic! Truly stands with the channel name'Dont Memorise' These videos are really helpful for class 11 and 12 children at places where teaching level is not good
Another way you can think of it as that there are 6! ways to be seated. However, in that arrangement, if you shift everyone 1 place to the left, the arrangement still appears the same. You can do this a total of 6 times before the arrangement goes back to the original spot. That's just how I thought of it but the method in this video is definitely easier to understand.
This channel cleared the most basic concept that we are afraid to ask the teachers sometimes or sometimes we cannot think of why it works..... Thanks a lot team.....keep it up.... And give ha the students a chance to ask you about most basic uncleared concepts
This is wonderfull Mam.. I just loved it.. The way u clarifies all. I was extremely in fond of this type of teacher... Coz I have so many questions regarding formulas... This makes me happy. 😊
When you sit on the second chair or the first chair or any of the 6 chairs the veiw is the same, no matter on which chair you sit it is the same condition. Another way of thinking is that you have 6 identical toys if you pick/choose (combination) any one the toys then it is the same way as they are the same.
Our aim is to make the concepts clear of the students. So we are glad that we could achieve this aim🙂 For more such videos stay tuned to our channel😃 Happy learning🙂
Amazing ways to make us understand….couldn’t understand combinations along with permutations before…..but after watching this playlist once understand it so much better…..they are easy to learn from….videos are awesome 👏
Your explanation are really amazing! I have seen all the RU-vid videos regarding this.no one can reach you.keep on uploading more of mathematical lessons.wish you a gooood future! By the way background voice is mesmerizing !!!!
Madam I like this very much I have seen all videos of other channels but I can't understand that what is happening.but I have learnt from your video . Thank you very much Mahadev har
Thank you ... This is good one. Can you please tell us if there is any shortcut for the question- If 5 letters are posted for 5 different addresses, how many ways are there for each of the letters to reach wrong addresses? Answer - 44
oh my god!!!!!!!!!! wow! brilliant and fastastical explanation. My teachers taught as if they don't want us to memorize but actuallythey never knew how to explain it to us so we truly understand why we subtract 1 from n. I thank God that I was patient enough to look through many videos before reaching this one. You have just made everything sparkingly clear! I relly appreciate it!
for those who did not understand----- draw out different arrangements and for all of those arrangements rotate the circle so that the first person is always on the top.
in case of linear permutations, we consider the things which are to be kept together as one element and then subtract it from the total no of arrangements to get the no of the arrangements when those things are not kept together.but in case of circular permutations, why doesn't this work?
This circle way is something that doesn't really make sense because every chair is different. Like this might be an analogy for a bigger problem. But I'll watch the rest of the videos.
You're most welcome Sudhansu. We are glad that you understood the concept. We are happy that we could help you learn. You motivate us to do better. Keep watching our videos. 😊😊
I've just got it, combination is all about the difference But that mean both of 1st person and 6th person have the same way which is 1? And it's 2 for 3 people!, but actually -1 doesn't work for that, right?
This only applies if the chairs are not distinct. If it was a real life situation, say 1 chair is in front of a window and the sun might be dazzling at that position, the other near a noisy table etc., the 1st person still has 6 ways of choosing.
Seriously Memorising not a good idea, Thank you for Visualise the derivation of this rule of arrangement aound a Circular Tablr or Circular element. Thank You So Much❤️
Ah so we have to anchor down the first person because the first person doesnt have anything to reference to, while the second person need to reference to person one. U except the first person out so that's why it is (n-1)!. This make remembering this formula much easier as u know what is going on. As if we have A, B, C,D. We want 4 letter combination where each letter is different. The good old method would be 4!. But pretend if there is a rule where first letter alway need to be A. Then we get 1!×3! Which arrive at 3!. And the formula of (n-1)! Do exactly this. 3!. This is 3:30am rn for me but thank you so much , now im gonna sleep in peace.
I find the formula (n-1)! for circular permutations a little incomplete. I say this because imagine a scenario where we have to seat 5 people around a circular table from a group of 6 people. In how many ways can this be done? So first we have to choose the 5 different people : 6C5 = 6 Then we have to arrange the 5 people around the circular table: which from the above formula = (n-1)! = (4)! So the answer is 6C5 X 4! = 144 (This is correct) But there is a hard and fast rule: Change the circular permutations formula to (nPr/r) For the example in the video, it becomes (6P6/6) = 5! - correct For my specific example, it becomes (6P5/5) = 144 - also correct, and possibly easier to remember. Just a tip. Nevertheless, fantastic video! I feel like I actually understand circular permutations now, so thank you DontMemorise! Subbed!
You're most welcome Nisha. 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. 😊😊
From 3:10 , why you have assumed all chairs to be identical. Suppose there are six chairs of different colours , then first person can sit in 6 different ways on 6 different chairs .
Please help me solve this question. In how many ways can six people be seated on a round table. b) how many ways are there if two people must sit next to each other?
