It is currently 20 Oct 2017, 11:08

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

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

can someone explain why you won't count 3-3 and 3-3 twice for dice?

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

Intern
Intern
avatar
B
Joined: 23 Jul 2015
Posts: 22

Kudos [?]: 2 [0], given: 0

Reviews Badge
can someone explain why you won't count 3-3 and 3-3 twice for dice? [#permalink]

Show Tags

New post 17 Nov 2015, 22:28
For example what is the chances John will roll a 6 by rolling two dice?
There are 36 outcomes and according to text 5 ways to roll a 6: 5-1, 1-5, 2-4, 4-2 and 3-3.
Why won't you count 3-3 and 3-3 like you do with 5-1 and 1-5?

Kudos [?]: 2 [0], given: 0

Math Forum Moderator
User avatar
P
Joined: 13 Apr 2015
Posts: 1503

Kudos [?]: 1112 [0], given: 884

Location: India
Concentration: Strategy, General Management
WE: Information Technology (Consulting)
GMAT ToolKit User Premium Member CAT Tests
can someone explain why you won't count 3-3 and 3-3 twice for dice? [#permalink]

Show Tags

New post 17 Nov 2015, 23:35
You can distinguish between 5,1 and 1,5. Say, in the first throw we got Dice 1 = 5 and Dice 2 = 1 and in the second throw we got Dice 1 = 1 and Dice 2 = 5. Here, even though the outcome is 6, we have two different ways to get 6. (2!/1 = 2)

But when we get Dice 1 = 3 and Dice 2 = 3 in both the throws, there isn't any significant difference between the two throws and the second throw can be considered as a repetition of the 1st throw. We can interpret this as 2!/2 = 1. So there is only 1 way when both the dices show up the same number.

Kudos [?]: 1112 [0], given: 884

Expert Post
1 KUDOS received
EMPOWERgmat Instructor
User avatar
P
Status: GMAT Assassin/Co-Founder
Affiliations: EMPOWERgmat
Joined: 19 Dec 2014
Posts: 9984

Kudos [?]: 3412 [1], given: 172

Location: United States (CA)
GMAT 1: 800 Q51 V49
GRE 1: 340 Q170 V170
Re: can someone explain why you won't count 3-3 and 3-3 twice for dice? [#permalink]

Show Tags

New post 18 Nov 2015, 15:43
1
This post received
KUDOS
Expert's post
Hi jasonfodor,

When rolling 2 dice, there are (6)(6) = 36 possible outcomes (including many 'duplicate' totals). They are...

11
12
13
14
15
16

21
22
23
24
25
26

31
32
33
34
35
36

41
42
43
44
45
46

51
52
53
54
55
56

61
62
63
64
65
66

The reason why you could 3-3 just once is BECAUSE it appears just once.

GMAT assassins aren't born, they're made,
Rich
_________________

760+: Learn What GMAT Assassins Do to Score at the Highest Levels
Contact Rich at: Rich.C@empowergmat.com

Rich Cohen

Co-Founder & GMAT Assassin

Special Offer: Save $75 + GMAT Club Tests Free
  Official GMAT Exam Packs + 70 Pt. Improvement Guarantee
www.empowergmat.com/

***********************Select EMPOWERgmat Courses now include ALL 6 Official GMAC CATs!***********************

Kudos [?]: 3412 [1], given: 172

GMAT Club Legend
GMAT Club Legend
User avatar
Joined: 09 Sep 2013
Posts: 16635

Kudos [?]: 273 [0], given: 0

Premium Member
Re: can someone explain why you won't count 3-3 and 3-3 twice for dice? [#permalink]

Show Tags

New post 19 Aug 2017, 22:45
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).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________

GMAT Books | GMAT Club Tests | Best Prices on GMAT Courses | GMAT Mobile App | Math Resources | Verbal Resources

Kudos [?]: 273 [0], given: 0

Re: can someone explain why you won't count 3-3 and 3-3 twice for dice?   [#permalink] 19 Aug 2017, 22:45
Display posts from previous: Sort by

can someone explain why you won't count 3-3 and 3-3 twice for dice?

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  


GMAT Club MBA Forum Home| About| Terms and Conditions| GMAT Club Rules| Contact| Sitemap

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne

Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.