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GMATPill
For anyone struggling to understand combinatorics and how this concept may show up on the exam, please learn these critical insights:


It is broken down as follows:

00:00 - Intro
01:00 - Warmup
02:12 - Part 1 Overview: Combinations & Permutations vs Variations
08:35 - Part 1 Details: Picking Teams, Dice, Pocket Pair, Dating
17:21 - Part 2: Apply to GMAT - Word Problem #1
22:13 - Part 2: Apply to GMAT - Word Problem #2
31:34 - Part 2: Apply to GMAT - Word Problem #3
38:04 - Part 3: Poker Probability - Pocket Pair vs Pocket Aces
43:40 - Part 3: Poker Probability - Given Pocket Aces, 3-of-a-Kind?
46:13 - Part 3: Poker Probability - 1-Pair by 5th Flop
49:59 - Part 3: Poker Probability - Full House/Flush
1:00:00 - Conclusion

Note: the Poker part is just for fun - you will not see poker questions on the test. But the prior 3 examples are game for the test.

I am stuck with 3 problems and the way they are solved:

1. How many distinct ways can 3 guys vote for those 3 girls? (variations)
Solved by considering the 1st guy can date 3 girls, 2nd guy can date 3 girls as well ...
3*3*3 = 3^3

2. How many potential dates can happen between 3 guys and 3 girls? (combinations)
3c1 + 3c1 + 3c1 = 9

3. How many different ways can 3 guys and 3 girls pair up for a group date of 6 people? (permutations)
3c1 * 2c1 *1c1 = 6

Can someone please help me understand what is the difference between the 3, as it is all about 3 guys choosing 3 girls, and why different methods are used
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I think this video is extremely helpful. Thank you Zeke! for making it available. GMATPill.
First time I find something really useful on combinatorics
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the GMATpill website doesn't seem to be working. Does anyone know about this?
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This video is not available now. How can we access it?
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Could this video please be made available again? If not are there any alternatives you would suggest?
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To all who stumble upon this thread only to realise that the main video posted by GMATPill isn't available, I suggest watching this video https://www.youtube.com/watch?v=redKVdUhO44 which is hosted on GMATClub's YT channel.
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Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

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