GMAT Ninja Quant Ep 16: Combinations & Permutations

Do combinations and permutations questions on the GMAT or Executive Assessment keep you up at night? Do you struggle to figure out whether a question is a combination question or a permutation question? Do the formulas leave you in a muddle?

Alternatively, are you aiming for a 50 or 51 in the quant section? Do you want to make sure you've left no stone unturned in your preparation?

In this video, Charles -- a veteran GMAT tutor with a perfect 800 score on the exam -- will help you develop a deep, intuitive understanding of combinations and permutations questions on the GMAT and EA.

The questions featured in this video will be gentle in the first half and tough in the second. The focus in the first half will be on your conceptual understanding. In the second half, Charles will dig into the variations the GMAT or EA could throw at you to make a combinations or permutations questions difficult.

This is video #16 in our series of full-length GMAT quant lessons. For updates on upcoming videos, please subscribe!

This video will cover:
➡️ Does order matter?
➡️ Intuition is more important than formulas
➡️ The basics you’ll need for a 47+
➡️ Hard questions (of dubious value)

This video is for you if:
➡️ You don't want to over study
➡️ Combinations and permutations keep you awake at night
➡️ You don't. know which formulas to use
➡️ You want a Q50 or Q51

Want more GMAT test-prep tips and advice?

Chapters:
00:00 Introduction
02:58 Question 1 - Permutations Warmup
09:03 Question 2 - Combinations Warmup
12:20 Question 3 - At least one
17:16 Question 4 - Turned inside out
25:04 Question 5 - Digits Part I
30:38 Question 6 - Only one from each
35:26 Question 7 - Digits Part II
40:51 Question 8 - One Digit Different
47:11 Question 9 - Around a Table

[utkarsh--kumar]

I went from 600 in the first official gmat practice test to 720 in the second practice test after just one week of learning from this playlist. Thank you and kudos to the gmat ninja team.

[vardanrathi]

In Q8, as soon as I saw greater than 4000, I knew a -1 would be coming to an even number of combinations. 215 is the only odd number in the answer choices :)

[bojos]

This video has much fewer likes than what it deserves. I wish this were the way P&C was taught at our schools. This is so much easier to understand.

[xunderoathx]

Why can I follow this way easier than regular probability? This makes perfect intuitive sense to me. Ah man, time to start the series over and go again! Thanks for everything!!

[pranavraj]

Hi Charles,
I gave my GMAT today and scored a 740 (V41, Q49). I wanted to thank you for your videos on Verbal and Quant. They helped me immensely, especially in Verbal. Your no Jargon approach in CR and SC helped me improve a lot. Focusing on meaning, instead of question types and fancy-named methods, helped me crack GMAT verbal.

Thanks a lot❤

Love from New Delhi, India

[morecratersthanmoon]

A key takeaway is how Charles checks for order matters or does not as a mandatory step before solving a problem. This is a good first step that can prevent mistakes early on. Very insightful video overall!

[gauravsahu]

my brain is fried and im nervous about how the exam will go but this playlist definitely helped me. Thanks Charles and the whole GMAT Ninja team.

[rejoicingGrace]

Thank you Gmat Ninja team for providing this series! Love these 19 videos and would rerun them later! :)

[harshitagupta]

Thank you so much for this video series! This series has helped me a lot!

[mr.moreawesomer]

Hello there! I want to say THANK YOU SO MUCH for all this content. I was really struggling with a bunch of topics on quant and also on Reading Comprehension / Grammar. I went through pretty much 30+ hours of your video content on this channel for free, and it was BY FAR the thing that improved my score the most. After 4+ months of grinding, I left the GMAT today with a 770 - absolutely unfathomable from the position I sat in only 2 months ago when I started your video. I am so grateful for this series and am recommending it to all my friends. Cannot believe you all did this for free. Again thank you so much GMAT Ninja Team!

[scentofthesea]

Another way to intuitively think about Q4 is that since the combination has to be 35, there has to be a 7 in it. Which means the only 2 options that we need to backsolve are 7 and 8.

[harishkrishnan]

Did anybody else look at the last question and immediately think of Will Smith !!😂

[anishakapoor]

I came across gmat ninja trying to find some lessons on CR but I can’t help but watch all the videos Charles teaches in.
What an amazing guy!
Cleared so many concepts.
Quick question; gmat still doesn’t go very deep into P&C questions? Asking since this video is about a year old and if anything has changed since then.

[frederickkingjnr]

A day after completing the quantitative playlist and without practicing further, i retook the gmat quant diagnostic test which i had taken in July last year. My scores in the first 24 was (6/24) and the second 24 which was data sufficiency was (11/24). Today it was (18/24) and (19/24). There's a lot of room for practice and improvement but thank you for the guidance :)

[slendermanky]

Thank you Charles, extremely helpful video!

[salvador]

Oh the way you ended the last question by saying you are getting bored by the explanation, i was like damn he read my mind. But the way you deliver things is something which just keeps me going.

Just went through the quant videos to just get in the groove before i give the official mock.

[vivekdesle]

Liked all the videos on Quants, RC & CR. It helped in getting the overall way to tackle the GMAT questions.Definetly recommending to other students to watch this videos
PS: While watching, not expected I will laugh so much/it made it that more refreshing

[hoatanky]

I have been preparing gmat quant for 1 month and have just finished this playlist, the gmat ninja quant prep course of yours, so far and I enjoy the way this course is organized. I am looking for something that categorizes Gmat quant into topics, subtopics with follow-up practice questions like your course. Can you suggest the next step as well as books to consolidate, improve my quant knowledge to begin solving quant questions? Thank you.

[karimmashad]

The fucking GMAT Boss!!! The MBAs community thanks you

[joyfulcancer]

GMAT Ninja -Thanks for the video. Re: Oscar inspired last problem. Your logic is : seat the non-slappers first ( 6 ways), put seats for the slappers, 4 seats that meets the constraint, work out how many ways you can seat the 3 people in the 4 chairs (4), and then work how many ways the 3 slappers can exchange the seats amongst themselves(3 )= 6x4x3=144.

say the circular arrangement is S1, NS1, S2, NS2, S3, NS3, NS4 ( S-Slapper seat, NS-Non Slapper seat). NS1 can be filled by 4, NS2 can be filled by 3 and NS3 and NS2 by 2 and 1 respectively. Combined 24 ways. Similarly S1, S2 and S2 in 3, 2 and 1 way.. total of 6. Combined 6x24=144. Is this logic correct ?