GMAT Combinations and Permutations Workshop

[@manishkrin]

I cannot describe in words how much you have helped me clear the difference between permutation and combinations. Please accept my sincere appreciation for your teaching method !

[@Tomahawk1999]

Dude i was getting lost in permutations n combinations and u really helped by showing everything in terms of multiplication and addition so i dont have to remember anything anymore. appreciate it a ton.

[@evan.5967]

Nice.

[@opeyemiadetula233]

One of the best videos on combinatorics ever!

[@insearchoftrance3590]

You've a life saver! Your tutorial got me to overcome my childhood fear of P&C, which I was hesitating to confront since the longest time. Could you please do one on Probability too, if possible?

[@TheTestedTutor]

Super clear and well paced, and I say that as a GMAT tutor who also does combinations videos.

[@Tomahawk1999]

hey could you please solve this one? If the word “WOW” can be rearranged in exactly 3 ways (WOW, OWW, WWO), in how many ways can the word “MISSISSIPPI” be rearranged?

[@SuperKidontheblock]

@@Tomahawk1999 We have altogether 11 words and out of which we have S - 4 times, I - 4 times, P - 2 times , M - 1 time then we can take 11! / 4! * 4! * 2! => 36450.

[@dhruvjoshi2063]

Sir, you're truly amazing. You explained the topics in such a clear and concise way, so much easier to understand than almost any other video of this topic on the internet now. It's so much easier to understand "why" you solve a problem than just memorizing "how" to do it, and the slots method is by far the easiest method to understand! Thanks for the help, you're a grade saver!!!!

[@rhd8124]

This is the greatest mathematical explanation I have ever seen... no joke

[@BryantCabrera]

Omg thank you so much! My GMAT is tomorrow and you are the only resource I’ve found that explained combinatorics clearly and concisely. Thank you!!

[@werder10100]

Great video. Tip for others: for the last exercise you do not need to do any further calculations after having calculated the number of games for the first round ;)

[@praneethchandu7236]

So helpful, you’re an angel for taking the time to make this! Sums up combinations well for GMAT prep

[@sachinsavailable]

Hi Sir! I must say you are a life saver. Never before has this topic been so clear in my life. I owe you one..... Thanks a million and keep up the good work. Cheers! and Regards

[@jesherpalomaria7996]

I've been struggling a lot with permutations, combinations, and probabilities in the GMAT. I'm still not a pro but this video certainly helped a great deal in my fundamental (rather than formulaic) understanding of the concepts. Thank you so much for this!

[@annsawyer6947]

I've watched several videos on probabilities and statistics and yours are the best in explaining these in a way that can be understood.

[@rahulbakshi5135]

Thank you for this! Explained the concepts better than MGMAT for sure

[@TheNinjaDwarfBiker]

The quality of this video is so high, thank you!!

[@contactrajdwivedy]

He just simplified combinations into different way of calculation and people are in awe :D For example question 7 better answered by 10C3-6C3..

[@josearturopacheco1154]

after going through a bunch of videos, this has been the best so far!!

[@evan.5967]

Great to hear!

[@benharper6805]

I bought Kaplan, and this was a much better explanation of how to attack these types of questions. Thanks for doing this video!

[@sudhansusingh2886]

This video has cleared all of my doubts.... Thanks for sharing.

[@classicsalted]

Awesome work sir! very clear explanation. Thank You so much for making this so easy. I don't know why you just stopped with only one video but this is just gold! I hope you really get back on us. KZbin is full of GMAT and CAT prep videos but I can safely say that those are all crap and discovering your's was just a miracle. Please make more videos. Your website does not work too. Please fix that and please help us.

[@evan.5967]

Thank you!

[@dhahamthi]

I am watching this to prepare for my freshmen year finals and thank you some much it super clear i recommended to my friends as well

[@svenbuchholz9862]

Best Tut for this stuff! Makes you really understand it instead of just using formulas

[@soumyadeeppal5317]

Your video really helped me to get a basic understanding of Permutation and Combination. Please make a video on Probability too. It will really help us.

[@gm4147]

Congratulations on your work. Great video. Rds

[@andersonfuller]

Very very helpful video. Great resource for those looking to improve at Combinatorics.

[@Abhaykk1994]

Really good method for solving combinatorics problem. Coverage of content was amazing to watch.

[@payalkhandelwal1816]

For Q4 identity codes for citizens, I think there are 2 groups.. Group1 = 4 or 5 alphabets + Group 2 = 5 least integers. So the code can have 9 or 10 characters and hence it should be (26^4+5^5)+(26^5+5^5). The way you have explained, it appears that the code only has 5 or 4 characters

[@upasnamalhotra3135]

such a sorted video about the topic i always found hard to cover. Great tutorial.

[@kritibakshi3338]

Great Video! Can you PLEASE PLEASE PLEASE PLEASE PLEASE PLEASE PLEASE do a video on Probability?

[@pratikmeshram6942]

yeah that bugs me too !

[@chibuzorbethel3292]

God bless you for making this video

[@juthirawnak1470]

You’re a life saver indeed 😊

[@thakgalangmphahlele5582]

Thank you very much for the effort and work to help students. We really appreciate the great work you does. FROM WITWATERSRAND UNIVERSITY IN SOUTH AFRICA.

[@evan.5967]

Hope this helped!

[@rohitchowdhury1815]

awesome tutorial sir, you made each concept crystal clear!! Thank You

[@evan.5967]

You're welcome, Rohit!

[@中国有习蛤]

You, sir, are a life saver

[@vaibhavmahabole3805]

Thank you very much...!! This was awesome. Please do one video for probability.

[@chrispeterson3464]

This video is top quality! Thank you

[@PK-wr6kz]

Excellent tutorial. Thanks for the wonderful insight. Any chance you create a video to cover Partitions & Permutations ?

[@nikitavishnevskiy1994]

Awesome video!

[@nileshkulkarni7150]

very good examples and explanatory, Thanks...

[@TShorty929]

Great video, great teacher!

[@trishamohanta4285]

Adam this was extremely well explained and just awesome!! Please upload more videos on GMAT quant topics!! Thank you soooooooo much :)

[@evan.5967]

Great! No problem. Happy to help.

[@zianiera]

Thank you for this great tutorial

[@TiltedPenguin292]

The third practice problem is worded badly. It says "is to have no two people representing the same country", not "two people or more cannot represent the same country." I thought 3 people, 4 or 5 people from the same country was allowed. To make sure no 2 people represent the same country, here's what I did: 25c4 (all possible combinations) - (5c2 * 5 * 4c2 * 5 * 5) = 5150 ways. Correct me if I am wrong.

[@jeffharootunian9975]

very clever way to present combinatorics. Just one question...In the problem that states How many 3 digit integers contain three different digits. Since integers can be positive or negative are you assuming that theses digits are to come only from the positive integer pool? What about the integer - 309. Is that not an integer? Do we need to account also for the three digit negative numbers as well? Thanks

[@xtype2006]

Amazingly clear explanation. Thank you so much!

[@evan.5967]

No problem!

[@arnabchoudhury2303]

This is so damn effective! Waiting eagerly for the video on Probability.

[@roshan1970]

Thank you very much! I learned a lot!

[@naeembawla9448]

Incredibly helpful! Wish the PDF was still available, but still great. Thank you

[@evan.5967]

No worries, Naeem!

[@imslogic]

In the last question, why didn't you multiply the games from each round following the ADD/MULTIPLICATION rule?

[@NishantSharmaxoxo]

we need more videos like this.

[@diabolikv2]

Great Video! Thank you very much! You really helped me understand the material!

[@CLLdj-h4p]

Bro I thank you so much

[@michaels6911]

Thank you for your videos ! Re: problem 2 Group of 3 from 5 married couples + no two can be married. Oops, I could be wrong here but from 10 people you are removing 3 each time. So shouldn't it be 10 x 7 x 4 ?

[@ratzibu3773]

Super helpful! Thanks a lot!

[@lucasdelbel7376]

Awesome video. I'm really grateful!

[@mahekparmar5193]

This helped me BIG BIG BIG TIME! Thanks man

[@mamo987]

awesome video seriously thank you

[@liamtahaney713]

This is a really great video thanks

[@lulemo145]

This is trully amazing and so clear. Thank you, thank you!!

[@rahulupadhyay3570]

Excellent video

[@ishaanchopra8340]

The best video I have seen on permutations and combinations. Hey Adam couldn't get through the link is there any other way I can contact you on your other gmat resources. Thanks for the video, great job man!!

[@shaxzodsaidov343]

Hi, For the question with married couple I got answer of 80 instead of 480. Becase, their place is not important, that is why I devided by 480 by 6

[@olamideayinde475]

Clear Explanation. Thank you so much

[@chitungip2157]

For keeping populations separate, is it for both arrangements and groups or for just groups? Thanks!

[@naeemrezaie]

In question number 6 does the arrangement of the 2 professors and 3 students in each committee matter? if it does'nt matter shouldn't divide by another two. 840/2= 420? I solved the question exactly the same as you did but I divided it by another two because of the reason I mentioned here. Thank you for the wonderful video by the way!

[@kaushaltolasariya]

Great Video! Quick Question: in the problem with chemists and biologists at 48:15 mins, my logic was to assume the first slot for a biologist (since order doesnt matter) and the rest in totality, so i got 4x9x8/3x2 = 48; clearly this wrong, but can you please explain why?

[@andrewgarfinkel7889]

that's not the right way to think about this one. Remember, you are dealing with 2 different groups (chemists and biologists), so don't add them up. You are looking for 3 person committees with AT LEAST ONE biologist---- that means you can have: 1 biologist OR 2 biologists OR 3 biologists. Calculate the number of groups for each different scenario and then add them. Go step by step... 1 biologist scenario, with 2 chemists: 4 x ( 6x5 ) / 2 2 biologist scenario, with 1 chemist: (4x3) /2 x 6 3 biologist scenario, with 0 chemists: 4x3x2/ 3x2 add them all up and you will get 100. hope this helps

[@kaushaltolasariya]

@@andrewgarfinkel7889 Thank you. Appreciate it!

[@zitongjin1088]

thank you so much for giving me a such great lesson on combinations

[@mehul4970]

thanks for the video buddy, it really helped

[@tourgazni2347]

very very helpful..thank you..

[@preetindersandhu2596]

Could this be another easier way to solve Question number 1 (Practice Review)after the review at time stamp 57:47. How about making 2 case scenarios and then adding the answers. The first scenario is when a Man sits in the first chair ; the second scenario would be when a Woman sits in the first chair. So there are 3 different ways to fill the first seat with the three men ,then 3 different ways to seat the three women in the second chair, then 2 ways for remaining two men to sit in the third chair, then 2 ways for remaining two women to sit in the fourth chair, then 1 way for remaining one man to sit in the fifth chair, then 1 way for the remaining one woman to sit in the sixth chair. That is 3M,3W, 2M, 2W, 1M, 1W and thus 3x3x2x2x1x1=36. The second scenario is when a woman sits in the first chair. Again using the same logic 3Wx3Mx2Wx2Mx1Wx1M and thus 3x3x2x2x1x1=36 ADDING the answers for the two scenarios, 36+36=72 is the answer

[@bsnundl]

Three letters from the word FREEDOM are selected and arranged in a raw. How many different arrangements of the 3 letters are obtained, given that repetition of letters is allowed. My answer is 216 and the answer provided is 215. A tennis club is to select a team of 3 pairs, each pair consisting of a man and a woman, for a match. The team is to be chosen from 7 men and 5 women. In how many different ways can the three pairs be selected? My answer is 7C3 x 5C3 but the answer provided is 2100

[@jerulyneaugustine465]

From that clear concept. How will I solve this question? Nine students are to have their photos taken, if they are to sit in a row, how many ways of arranging them are possible?

[@sijabulilehappinessndlovu7559]

Thanks a million man. This was very helpful!!!

[@sunnyrx7]

For question 3 . How many 3 digit Integers contain 3 different digits?. Since the question said " integers " and not " positive integers" ., should the answer be (648*2) to include the negative integers of the same set??

[@shagun.sharma]

Same opinion. In my view too, -123 should be a valid answer to the problem (3-digit no., different digits)

[@toopidipoo1153]

Hi, thank you for the video. I am not sure if anyone will reply. For #6 with the problems portion of the video, in the text they said the game of chess will be with “every other player”. When I read it, I thought that player 1 will play with player 3, then player 2 would play with player 4, player 5 would play with player 7, etc... I am not a native English speaker, but I thought every other player would be just as every other day. How do I prevent myself from making a mistake like that on the test? Any tips? Thank you!

[@shubhampansari]

This video helped me so much. Thank you :)

[@anapoilievre]

Really great! But I can't get the website to work. I'd like to practice more.

[@Freak51214]

thank you so much, really appreciated your work!

[@evan.5967]

Haha, thanks!

[@abhishek0mecengg]

Gud explanatory video. But I believe one question is solved incorrectly here. Question at 21.15 asks about the total no. of integers...not just positive integers..it could be negative too. So the correct answer should be= (no. of positive integers satisfying the condition + same no. of negative integers) i.e. 648*2=1296. Please correct me if I am wrong here.

[@ayanguray570]

Thanks for Somali Please need more videos about different topic

[@sonalbodelle5226]

I have got a doubt in that professor and student committee question. Can we connect over gmail??

[@SM-ku3uo]

your videos are sooo helpful! better if you can also teach us the short cuts. like 6! 6C2 etc..

[@SM-ku3uo]

actually i realized you dont need to know 6C2 etc if we learnt just what you said :)

[@aj1234productions]

Amazing Video!!!

[@sunnyrx7]

For Question no: 6 - to for committees 2 professors and 3 students . After you get 840, 840 represent the arrangements and to get the group we divide by 2. = 420 committees. Am I right?

[@eczionscarletgem1579]

Thank you so much, you're a life saver 🥰

[@evan.5967]

Haha, nice!

[@San-sandy]

how the problem 2 diff from problem 8 apart from the or condtion ?

[@layelltaief5398]

Question about problem #3 : integers include negative numbers, but this solution only accounts for positive integers. Did I miss something? Otherwise helpful video thanks!

[@ashishsinha9035]

Very good!

[@johnblahut4912]

Very helpful - thankyou.

[@shreyashkashyap2]

This is gold.

[@jayantimishra9008]

Thank You. The video is great.

[@carlosvillacis3762]

iF THE PROBLEM NUMBER 5 SAYS EITHER OR WHY NOT USING THE ADDITION RULE?

[@789anmol]

Amazing amazing video.

[@londonl9995]

This is great!!

[@negodoy]

Great video!!!! Thankss !!

[@femiprotokol2542]

This is great ! Thanks.

[@harikajanjanam1185]

Thank you 😊

[@tulikatanya64]

Very helpful

[@mithilparopkari8375]

Maybe question is framed incorrect? "In how many different ways can three of the five letters A, B, C, D and E be arranged, if no letter(?) is repeated?" "....., if no "arrangement" is repeated?"

[@FunTycoon134]

Very helpful, thank you!!