GMAT Question of the Day - Daily to your Mailbox; hard ones only

It is currently 19 Oct 2019, 00:09

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

Two fair dice are thrown together. what is the probability that the nu

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

Hide Tags

Find Similar Topics 
Intern
Intern
avatar
Joined: 02 Sep 2015
Posts: 4
Two fair dice are thrown together. what is the probability that the nu  [#permalink]

Show Tags

New post 22 Sep 2015, 18:18
4
00:00
A
B
C
D
E

Difficulty:

  75% (hard)

Question Stats:

55% (02:13) correct 45% (02:43) wrong based on 84 sessions

HideShow timer Statistics

Two fair dice are thrown together. what is the probability that the number obtained on one of the dice is a multiple of the number obtained on the other die?

A) 11/18
B) 5/18
C) 5/9
D) 8/9
EMPOWERgmat Instructor
User avatar
V
Status: GMAT Assassin/Co-Founder
Affiliations: EMPOWERgmat
Joined: 19 Dec 2014
Posts: 15281
Location: United States (CA)
GMAT 1: 800 Q51 V49
GRE 1: Q170 V170
Re: Two fair dice are thrown together. what is the probability that the nu  [#permalink]

Show Tags

New post 22 Sep 2015, 20:36
1
1
Hi rverma007,

What is the source of this question? I ask because you've listed just 4 answer choices, which is not realistic. If you're studying from material that is not proper GMAT material, then you could very well be hurting your chances at scoring at a high level on the Official GMAT.

Regardless, here's how to answer this question. Each of the two dice has 6 possible outcomes (1 - 6, inclusive), so there are (6)(6) = 36 possible pairs of dice rolls.

We have to figure out how many of those pairs include a number that is a multiple of the other number. We can list them out:

1,6 and 6,1
1,5 and 5,1
1,4 and 4,1
1,3 and 3,1
1,2 and 2,1
1,1

2,6 and 6,2
2,4 and 4,2
2,2

3,6 and 6,3
3,3

4,4
5,5
6,6

22 of the 36 options fit the description of what we're looking for. 22/36 = 11/18

Final Answer:

GMAT assassins aren't born, they're made,
Rich
_________________
Contact Rich at: Rich.C@empowergmat.com
Image


The Course Used By GMAT Club Moderators To Earn 750+

souvik101990 Score: 760 Q50 V42 ★★★★★
ENGRTOMBA2018 Score: 750 Q49 V44 ★★★★★
Veritas Prep GMAT Instructor
User avatar
V
Joined: 16 Oct 2010
Posts: 9706
Location: Pune, India
Re: Two fair dice are thrown together. what is the probability that the nu  [#permalink]

Show Tags

New post 23 Sep 2015, 09:48
1
1
rverma007 wrote:
Two fair dice are thrown together. what is the probability that the number obtained on one of the dice is a multiple of the number obtained on the other die?

A) 11/18
B) 5/18
C) 5/9
D) 8/9


You can go the other way around:
Find the pairs in which neither is a multiple of the other.
Ignore all pairs with 1 since the other number will be a multiple of 1.

If one number is 2, the other can be 3 or 5. So two possible options. We could have 2 on the other die so total 4 options (2, 3) (2, 5), (3, 2), (5, 2).

If one number is 3, the other can be 4 or 5. Again, there will be 4 total options.

If one number is 4, the other can be 5 or 6. Again, there will be 4 total options.

If one number is 5, the other can be 6. There will be total 2 options.

There are total 4 + 4 + 4 + 2 = 14

Probability that neither is a multiple of the other = 14/36 = 7/18

Probability that one number is a multiple of the other = 1 - 7/18 = 11/18

Answer (A)
_________________
Karishma
Veritas Prep GMAT Instructor

Learn more about how Veritas Prep can help you achieve a great GMAT score by checking out their GMAT Prep Options >
Non-Human User
User avatar
Joined: 09 Sep 2013
Posts: 13264
Re: Two fair dice are thrown together. what is the probability that the nu  [#permalink]

Show Tags

New post 08 Apr 2019, 19:38
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 Club Bot
Re: Two fair dice are thrown together. what is the probability that the nu   [#permalink] 08 Apr 2019, 19:38
Display posts from previous: Sort by

Two fair dice are thrown together. what is the probability that the nu

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





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