Last visit was: 26 Jul 2024, 21:19 It is currently 26 Jul 2024, 21:19
Close
GMAT Club Daily Prep
Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track
Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Close
Request Expert Reply
Confirm Cancel
SORT BY:
Date
Tags:
Show Tags
Hide Tags
SVP
SVP
Joined: 14 Apr 2009
Posts: 2261
Own Kudos [?]: 3702 [35]
Given Kudos: 8
Location: New York, NY
Send PM
User avatar
Senior Manager
Senior Manager
Joined: 07 Apr 2014
Status:Math is psycho-logical
Posts: 334
Own Kudos [?]: 395 [1]
Given Kudos: 169
Location: Netherlands
GMAT Date: 02-11-2015
WE:Psychology and Counseling (Other)
Math Expert
Joined: 02 Sep 2009
Posts: 94619
Own Kudos [?]: 644181 [3]
Given Kudos: 86770
Send PM
Intern
Intern
Joined: 04 Oct 2016
Posts: 15
Own Kudos [?]: 5 [1]
Given Kudos: 120
Send PM
1 hour Combinatorics Video Lesson [#permalink]
1
Kudos
GMATPill wrote:
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
Manager
Manager
Joined: 22 Jun 2017
Posts: 238
Own Kudos [?]: 663 [0]
Given Kudos: 149
Location: Argentina
GMAT 1: 630 Q43 V34
GMAT 2: 710 Q50 V36 (Online)
Send PM
Re: 1 hour Combinatorics Video Lesson [#permalink]
I think this video is extremely helpful. Thank you Zeke! for making it available. GMATPill.
First time I find something really useful on combinatorics
Intern
Intern
Joined: 05 Mar 2022
Posts: 2
Own Kudos [?]: 0 [0]
Given Kudos: 3
Send PM
Re: 1 hour Combinatorics Video Lesson [#permalink]
the GMATpill website doesn't seem to be working. Does anyone know about this?
Intern
Intern
Joined: 31 Jul 2021
Posts: 18
Own Kudos [?]: 15 [1]
Given Kudos: 62
Location: Pakistan
GMAT 1: 730 Q48 V42
GPA: 3.31
Send PM
Re: 1 hour Combinatorics Video Lesson [#permalink]
1
Kudos
This video is not available now. How can we access it?
User avatar
Intern
Intern
Joined: 13 Nov 2022
Posts: 1
Own Kudos [?]: 0 [0]
Given Kudos: 0
Send PM
Re: 1 hour Combinatorics Video Lesson [#permalink]
Could this video please be made available again? If not are there any alternatives you would suggest?
Intern
Intern
Joined: 11 May 2023
Posts: 38
Own Kudos [?]: 13 [0]
Given Kudos: 25
Location: India
Concentration: Technology, General Management
GMAT 1: 670 Q47 V35
GMAT 2: 650 Q47 V35
Send PM
1 hour Combinatorics Video Lesson [#permalink]
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.
GMAT Club Bot
1 hour Combinatorics Video Lesson [#permalink]
Moderator:
Math Expert
94619 posts