Combinations and Permutations Word Problems
Vložit
- čas přidán 5. 08. 2024
- Combinations and Permutations word problems.
Stuck?
Go to the youtube playlist:
• permutations and combi...
To donate to the tecmath channel:paypal.me/tecmath
To support tecmath on Patreon: / tecmath
To buy tecmath mechandise: teespring.com/stores/tecmath-...
What a teacher! Cheers mate! My kids think I'm brilliant! When they're older I'll tell them the truth!! All the best and keep doing great things!! Thank you!!
John Cummins lol
What a dad
Man, i think some fathers are better than others. And you are good one 😂
We all learn from someone else, unless we invent it, but then we are still using others' ideas
when your teacher is a youtuber
Since 2020
Since 2022
Since 2019
Finish the thought.
Dude, I figured out how to do permutations and combinations just by looking at the thumbnail
Also like if you're watching in 2019
big brain gang
There are harder problems than these.
2021 so im from the future aka the present
Lmao fr
2021? Bet
it's still confusing. for e.g. the first question when picking 3 out of 7 songs, order for me doesn't matter. the question is asking to select 3 songs which are to be played, so it can equally be a combinations questions where we pick 3 songs and none of the songs are repeated so long as we have 3.
Yeah, u do have a substantial point there. Unfortunately, logic doesn't always plays out right
but they ask you in how many "different ways" this selection can be done. so surely, order does matter.
I'm with you. The way the question is worded implies that e we are just picking the songs, not talking about an arrangement of the songs.
@@fathimarifa507 But on the card dealing problem it is worded the same (ie "different ways") but on that one order does not matter. Ive run into these ambiguities quite a lot studying for the GED and it just seems to be based on the whims of those writing the questions.
Felt like just the other day I watched videos on this channel to pass my algebra regents, now I'm doing statistics. Time flies.
I have not yet found anyone on the internet who explained this easier and better than you did!!! This was AMAZING!! Thank you sir!!
I love how you teach sir very brief yet so easy to understand
Paid for a GRE prep course for the math portion. These videos are doing the trick instead! So appreciated! Thanks!
unfortunately, the first 2 problem are wrong. Don't know about the rest as I stopped watching after finding first 2 wrong.
A seemingly difficult topic was very easy in reality! Thanks sir.
Thanks for the extra comb and perm word problems! It helped me a lot on the math comps.
I wish u r my math tutor or teacher.. Then I will retain my A grades my whole life
Thanks alot darn a whole 3hr lecture understood in minutes... thankyou ☺️✅
Still confused about when order matters vs when it doesnt matter.... can anyone give me a trick to determine when it matters and when it doesnt?
This is very helpful and the examples are excellent. Thank you
Watching it some hours to exams and am greatful it has really help
I could watch you write all day long. The numbers/shapes are so neat and natural it's mesmerizing... A big improvement from the horrendous oversized scratchy felt marker on paper *cringe*
I love these videos, keep 'em coming
Hello, thank you for a great video. I have a question about the final problem. How come there are 6 ways of ordering the group of people the same way, rather than 5? I thought that once the person returns to their original seat then this change shouldn't be counted as it is the same (eg ABCDEF returning to ABCDEF, as opposed to the other similar cases like BCDEFA) Thank you in advance
You explained this so clearly!
This was so perfect! You are amazing and yooooo, that accent is dope. :)
Thank you. Hope it helped
Brandon u mean the low pitched voice? Because the accent sounds like a normal American one.
it’s not normal american...more like australian or new zealander...
I like your style. Thanks very much for sharing
5:55 we answered that yesterday and Got the correct answer😀😀😀...
Thank you for the easier step
A permutation is a set of all possible arrangements of some or all objects from the collection, when the order of the selection of objects from the collection is important. The combination is a selection of objects from the collection, such that (unlike permutations) the order of selection from the collection does not matter. For example,
• Fruit salad of apples, grapes and bananas is a combination. If we do not care what order the fruits are in, then they could also be "bananas, grapes and apples" or "grapes, apples and bananas", it is the same fruit salad.
• Selection of the five number of peoples for the team is a combination. You could order them by names, heights or something else, but essentially you would still have the same team, ordering is irreverent.
• The ATM pin code “1234” is a combination. Now we do care about the order. The orders 4321" or "3412” would not work. It has to be exactly “1234” for opening the ATM machine.
The languages that are more precise in counting techniques are the following:
• If the order does not matter, then it is a combination
• If the order does matter, it is a permutation
for the camp fire question, why it is divided by 6 but not minus 6? I'm still confused.
It's not just the six similar positions he showed. For every possible arrangement there are 6 redundant positions. Does that make sense? Consider his example but switch two people. Now rotate them. You will find 6 more redundant positions. This means you need to divide the total number of arrangements by 6 redundant positions for every arrangement.
Anybody else here the morning of a test and learned this literally within 5 minutes of watching?!! What is my professor doing?
Thank you so much😊
It helps me a lot
OMG I am lookning at helping my son with MQM 100 and I actually understand this
by the way you teach I am like it can't be this simple ?
For the first question surely you need to divide by 3! to take into account the different orders of songs? 210 ways includes 3! ways of doing the same 3 songs just in a different order?? Then for second question, surely you would NOT divide by the 3! because giving 1st and 2nd and 3rd in a different order means giving different horses different places - order IS important here so you DON'T divide. Am I reading the questions wrong and going crazy here or are your permutations and combinations a little muddled???
so true. :( I'm also getting wooho crazy
I agree
I think this video is wrong ;(
For the the 1st question i believe he left off that you should divided the 210 by 6 which will give you 35 ways since it is a combination problem. If you were to check it on your hand held calculator you can do this.
Calculator functions:
press MATH
go to PROB
press nCr
then enter the nCr
His answers for 2 and 3 are correct, but I'm unsure about question #4 with the MISSISSIPPI since i got lost myself.
Just a suggestion if this video confused you and did not help you to get a better understanding i feel you should try this one instead czcams.com/video/X9-Yjxt6nf4/video.html&pbjreload=10 i think he breaks it down better.
Pretty sure that on the first question, you need to do 7 3 NCP, since the order doesnt matter. and for the answer you will then get 35. so yeah, he is wrong
i still have no idea how to figure out if the order matters or not
Why does the order matter when you're sitting around a campfire?
In the first question, why is it you used permutation? The problem is not in order it must be combination. Am I right?
I WAS ABOUT TO COMMENT THIS!! I'm so confused as to why he did that.
Same here :((
I think it's bc it 3 specific songs to perform ...not sure though I'll look more into it
It should be combination
@@heartfieldlamadrid8187 think of it as no song should repeat which is why it became a permutation question
U MADE THIS FREAKIN PROBABILITY VERY EASY
Can you please explain it in details I do not see why and how you cancel the numbers when multiplying.
oh man...i'm only the third comment!
Vani Ahuja watch his combinations video. It's because the formula for combination is n!/(n-r)!r! n is the number of items, r is the number of place or digits to be filled. For example: pick 3 supercars from 50 supercars. 50 is the n, and 3 is the r. That's for comvination.
Lol its not a race
The last question could simply be:
Circular permutation, because it is talking about ( around a campfire).. anything that talks about circle use this.
Formula: (n-1)!
•how many ways can 6 people sit around a campfire?
6-1= 5! = 120 ways
Sips Tea thanks hope it works on the test
Thanks dude!! Much ❤ to you.
There is a reason for this.
For every permutation, you can rotate it and form another. So for n permutation, you have n duplicates.
So you simply do n!/n which is (n-1)!
Yaaaas boss~! So clean!
The schools need this guy
you explained it very well superb
Why order matters when singer gonna choose songs to sing? Anyway he will sing 3 of them, doesnt matter which one is first or last
Are you suggesting that song arrangement on an album or a concert set list isn’t important?
Thank you!
Spot on videos!
Your letters are cute. I love it
Thanks i feel as if i know 100% now !
1:40 they've already sung one the songs in this spice hiya
This was the easier one but my teacher gives us the harder one with solutions. Well thanks for tgis
i think your voice made this easier to understand
There's some confusion about the first example---tecmath is right, it is a permutation. Think of it as making a playlist. Keyword here will be "list". The order matters because otherwise it's a different performance, a different concert if you will.
No. If 3 songs are chosen, let them be A, B and C, and the order in which they are choose can be ABC, BAC, BCA etc. They are still the same songs just in different order. You can perform A, B or C in any order. Therefore, Order does not matter. It is a combination as ABC, BAC, BCA are same and has to be divided by 3!.
Lets take your example of "LIST". Suppose u have 3 songs in a list, u can play them in any order so order does not matter.
But If the question had specified that the song A has to be played 1st, B 2nd, and C 3rd then ABC, BAC, and BCA will be different
(this is what u r assuming and what techmat assumed without specifying in the question) then it would be permutation.
Moreover techmat swaped the methods of first 2 question (don't know about rest as I didn't watch).
The second question has to be solved using permutation in which he used combination
this was helpful ty
Good work
chill dude, good math :)
I have five cats that like to go outside. How many combinations would that be if one cat can go outside, and 2 and 3 and 4 and 5? I'm not sure how to do this one.
Is it 5! ?
Thank you for this. I still don't understand why in example 5 ('How many different ways can 4 fruits be selected from 6 for a salad?') The top number order stops at 3 and does not go all the way to 1 (6x5x4x3 instead of 6x5x4x3x2x1). I'd be grateful if anyone could explain why this is the case.
Can so.eone awnser me, WHEN DOES THE ORDER MATTER. I know how to calculate it I just don't know which formula to use because I can't tell when the order matters
Similarly the second question solution is wrong, that is NOT a combination but a permutation problem. 3 horses are chosen for 1,2,3rd positions so ABC is not the same as BAC or CAB. correct answer is 12 x 11 x 10 = 1320 and not 1320 / 3 ! which would be the no of all possible ways 3 horses could be chosen from a group of 12 horses.
Thank you 😘😆😉
I don't get it at all, but I think there's something wrong there. I'm glad that I read the comments. I knew something was up. I just couldn't figure it what or why.
What a life saver
hey.....can you make a video on how to multiply three 2-digit numbers in mind...
Great video, but I wouldn't agree with the last one in assuming that rotating them doesn't count. If we wanted to assume that it should be in the wording, not the explanation.
Thank you beybeh
U R AN AMAZINGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGG TEACHER !!!!!!!!!!!!!!!!!!!!!!!
Thanks for this video! Just one question, what’s the difference between the first exercise with the songs and the third one with the cards? Why is the first one permutation and the third one combination? In other words, why does order matter in the first one (since it’s a permutation) and it does not matter in the third one (which is a combination)? Thanks in advance and thanks for the great video!
I guess with songs the set list does matter!
i think its a permutation in both cases. many times the only difference between going w perm or going w comb is just the way the qn is worded. both mentioned "different ways" in which the objects could be chosen, meaning order does matter. and usually, combination is calculated on qns where the objects are indistinguishable, like say choosing 2 out of 5 green balls. clearly, it doesnt matter which ball you choose first there.
Thanks❤👍🦋🌸💜
This beat me
But love the channel
in how many ways two books on five shelves so there is not more than one book on a shelf?
If the books are identical, then there are ways.
If the books are all different, then there are ways.
how to do this?
You're the best
Is it just me or does he sound like a flight attendant on the intercom? Anyways, great vid mate!
Astrx Playz oh mygod he does hahahaaahahhah
For the campfire problem, you could have set one person as the reference point, and the rest is a factorial. 5!= 120. This is an easier method imo!
I like it!
thanks
for the last problem why did we divide the factorial of 6 by 6? for the other permutation questions we divided by a factorial, why was this not necessary for the last problem?
+Prince of Puntland permutations in a circle.
If I wanted to arrange 4 objects I can do it 4! ways (24 ways).
If the 4 objects are in a circle they can be arranged 4!/4 ways....we divide by 4 because the rotated arrangements are considered to be the same. 24/4 = 6 ways.
Unsure still...look at the last problem in my permutations video ( link to playlist is included in the description of this video). It should help.
tecmath but what is it wasn't a permutation in a circle
For example the guy on the top of the camp fire goes at the place of the guy under the campfire
Does ur technique still work?
I have a question:
The first question about songs. You did not include a factorial denominator, why? It seems to me that order DOES NOT matter in this question just as question 3 where you DO include a factorial denominator.
How are "cards dealt" any different from "songs performed"? The order is irrelevant in both cases, you end up with a group of 3 or 5.
What is the difference, please?
I’m literally still confused I mean for the first ex I kinda understand that you rlly can’t play the same song 3 times but then again you can do that. It’s like this question I have for hw, 8 ppl apply for 3 different jobs at a company. I mean it kinda sounded like a permutation but it rlly doesn’t matter who gets what job. Or idk. Can someone help me understand cuz I’m super unsure
Def not an expert myself, but I'm going to try to help you out a bit (albeit a tad late innit). Think about it this way: there are 8 people applying for 3 different jobs. It helps to think like he did, with underlines. Three jobs, so three underlines: _ x _ x _. In the beginning, there are 8 people who can get the job: n(ways 8 people can be hired for 3 jobs)= 8 x _ x _. Now, the first person hired can't be hired again, which means there is one less person available: 8 x 7 x _. The first person and the second person hired can't be hired again, so we have to subtract 2 people from the total candidates available. That leaves us with 8 x 7 x 6 = 336. There are 336 ways 8 people can be hired for 3 jobs. The problem is a permutation cause the order matters, aka the same person can't be hired more than once. A combination is when the order doesn't matter. Hope this helped!
Why on the song question, You didnt divide anything?
What happened to the last question??? Why did you divide it by 6?
Same! I'm confused
Vergel Gundran becaause the formula for circular permutation must be divided on its n
What if I have 3 styles of mashed potatoes and can be cooked in 3 different textures, and can be flavored 5 different ways, how many ways can I order my mashed potatoes?
Awesome!!!!!!!!!!!!!!!!!!!!!
Why is third question with the card a combination? Shouldn't the order matter because we can have one card be in the 4th position or the in 7th position?
Ohhh wait nevermind I read the question incorrect mb lol
Can you these questions where one person can't from another person in a round table. That was what given to me in my exam. I don't think I got it.
I cant be the only one thinking that you sound like Jeremy Clarkson!!
Why does order matter in the “Mississippi” example, but order doesn’t matter in the “deck of cards” example? The questions seem similar to me.
So is the Mississippi problem a combination or a permutation?
Foy Foy permutation w/ repetition
You sound like Birdie from Hitman Absolution xD... Anyways nice video
I don't understand why you have to divide it, why couldn't you just leave it as 6x5x4x3x2x1 for example?
Nice way of explanation... 👍🏻 #MathsPathshala
Why is the last example divided by 6? If its a permutation, shouldn't it be 6!/(6-6)! == 6!/0! == 6!/1?
i think because its six people choose six seats, the permutation is 6!/(6-6)! and he just omitted it for simplicity.
and since six people sitting in a round table, there are six specific arrangement. so you need to divide by six.
In a restaurant the first dish costs 0.80 euros ,the main dish costs 2.40 euros and the dessert costs 1.20 euros.3 friends ate and paid a total of 10 euros.Each of them ate at least 2 out of 3 dishes.How many first dishes,main dishes and desserts did they buy?
I couldn’t get past him sounding like the Geico gecko 🦎
Great video! I was just wondering in question 4, is there a way to type this directly into the calculator with 11P (1,4,4,2) if you understand what I mean or do you have to type it out like you did?
good..☺ need subtitles too..
I dont thing you can
1. Write a program that accepts an integer input from the user and display the least number of combinations of 200s, 100s, 50s, 20s, 10s, 5s, and 1s.
[Test your solution using this samples]
a. Input: 250
Output: 1x200s, 1x50s
b. Input: 1127
Output: 5x200s, 1x100s, 1x20s, 1x5s, 2x1s
c. Input: 1127
Output: 5x200s, 1x100s, 1x20s, 1x5s, 2x1s
d. Input: 19
Output: 1x10s, 1x5s, 4x1s
[Hints]
o Use division to determine the number of occurrence of each element (i.e. 200, 100) in the input (e.g. Given 500 if we divide it by the largest number possible; which is 200; we will get 2. Therefore, there are 2x200s.)
o Use subtraction to determine the remaining value of the input. (e.g. In the 500 example, since there are 2x200s, we still have 100 to process. The 100 came from 500 - (2*200) = 100.)
o Use the next largest number possible (i.e. 100) to check the number of occurrence. Continue until the remaining value of the input is zero.
pls help me
Integration and differentiation is far easier than counting😓😓
Dude..... The Mississippi one had me ⚰️
Went over it 6 times and still don't understand it
That is the total different permutations or anagrams of that word using all the letters. What they never explain or mention is part permutations. What if u want to know how many permutations of 4 letters can be made from that word? Pretty hard writing them out by hand. So what is the math solution?
I can tell u there are 11 different 1 letter words, and 34,650 different 10 letter words. That's it.
There are 11 alphabets so 11!.. And there are 2 p's, 4 i's and 4 s's ..These can cause duplicates when we arrange the word MISSISSIPPI. So we divide with 2!*41*4! and thus duplicates are not created.
Can u pls tell.. In how many ways 5 letters can be posted to 5 different wrong addresses ?
I can't tell if I'm here more so for the advice or the Australian accent.
The accent.
Teachers are stupid teaching us how to do it the hard way its like they want us to have bad grades
That's right and they are
Doing it the hard way is more of like a 2-way street, it can be good, ooor it can be bad... But this is my opinion on the matter anyway.
the problem is teachers teach us the literal barebones of the lessons and they want to call it the "basics" then make some stupid crazy wonder questions in the test papers... i suppose students got to study longer in home than school
Well... first of all, it's*, learn to speak English. Also, do you even think before typing?
lol our teacher literally include the problems in our quizzes which are meant to be taught to us a week after
thankyuuuu
I think the answer on the 2nd last question is 30 bcoz 3 and 2 can be divided by 6 in which in ur case you did not compute intirely and if the answer is really 15 then how come the number 3 below in being canceled? Nice vid though very helpful and educational.😊
So is #2 a permutation? Did not make that clear.
i dont get it
It helps me a lot.
But I don't understand some words that you are saying because your so fast😂
Am I the only one who HATES these and when I think of Hell I picture a math professor handing these out at a unsolvable rate.