NEW HERE? LEARN MORE
closeclose
Last visit was: 26 Apr 2024, 18:56 It is currently 26 Apr 2024, 18:56
Decision Tracker
My Rewards
New posts
New comers' posts

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.
Go to My Error Log Learn more
Close
Request Expert Reply
Confirm Cancel

What is the probability that exactly two of the six numbers appear on

User avatar
D
udaypratapsingh99
Senior Manager
Senior Manager
Joined: 12 Jan 2019
Posts: 404
Own Kudos [?]: 216 [2]
Given Kudos: 372
Location: India
Concentration: Strategy, Leadership
Schools: Fuqua '24 Harvard '24 LBS '24 NTU NUS Said '23 Ross '24 Sloan '24 Stanford '24 Tepper '24 Tuck '24 Wharton '24 Yale '24
GMAT 1: 660 Q47 V34
Send PM
Reviews Badge CAT Tests
What is the probability that exactly two of the six numbers appear on [#permalink] New post   12 Jan 2019, 08:56
2
Bookmarks
00:00
A
B
C
D
E

Difficulty:

75% (hard)

Question Stats:

40% (02:22) correct 60% (01:38) wrong based on 10 sessions
Hide Show timer Statistics
What is the probability that exactly two of the six numbers appear on the top face in the six throws of an unbiased die?

a. \(\frac{1}{729}\)

b. \(\frac{15}{729}\)

c. \(\frac{155}{6^5}\)

d. \(\frac{13}{729}\)

e. \(\frac{2}{243}\)

Archived Topic
Hi there,
This topic has been closed and archived due to inactivity or violation of community quality standards. No more replies are possible here.
Where to now? Join ongoing discussions on thousands of quality questions in our Problem Solving (PS) Forum
Still interested in this question? Check out the "Best Topics" block below for a better discussion on this exact question, as well as several more related questions.
Thank you for understanding, and happy exploring!
ShowHide Answer
Official Answer
C
User avatar
D
udaypratapsingh99
Senior Manager
Senior Manager
Joined: 12 Jan 2019
Posts: 404
Own Kudos [?]: 216 [0]
Given Kudos: 372
Location: India
Concentration: Strategy, Leadership
Schools: Fuqua '24 Harvard '24 LBS '24 NTU NUS Said '23 Ross '24 Sloan '24 Stanford '24 Tepper '24 Tuck '24 Wharton '24 Yale '24
GMAT 1: 660 Q47 V34
Send PM
Reviews Badge CAT Tests
Re: What is the probability that exactly two of the six numbers appear on [#permalink] New post   12 Jan 2019, 09:01
\(\frac{(6C2x(2^6-2))}{6^6}\)
User avatar
B
rajatvermaenator
Intern
Intern
Joined: 15 Nov 2018
Posts: 44
Own Kudos [?]: 6 [0]
Given Kudos: 53
Location: India
Concentration: Operations, Finance
Schools: Carey Arizona "22 (WA$) McDonough '22 (A) Schulich "22 (A) Broad '22 (A$) Kelley '22 (A$)
GMAT 1: 710 Q49 V39
GPA: 3
WE:Engineering (Transportation)
Send PM
Re: What is the probability that exactly two of the six numbers appear on [#permalink] New post   12 Jan 2019, 10:33
What is the probability that exactly two of the six numbers appear on the top face in the six throws of an unbiased dice?

Ans: total ways = 6^6
Selecting any 2 number : 6c2
Lets say two numbers selected be : a and b out of 6, then in 6 rolls:
Case 1: a,a,a,a,a,b or b,b,b,b,b,a
No of Ways- 2*6!/5!

Case 2: a,a,a,a,b,b or b,b,b,b,a,a
No of Ways- 2*6!/4!*2!

Case 3: a,a,a,b,b,b
No of Ways- 6!/3!*3!

Totalling we get : 62

Ans : 6c2*62/6^6 = 155/6^5

Posted from my mobile device

Archived Topic
Hi there,
This topic has been closed and archived due to inactivity or violation of community quality standards. No more replies are possible here.
Where to now? Join ongoing discussions on thousands of quality questions in our Problem Solving (PS) Forum
Still interested in this question? Check out the "Best Topics" block above for a better discussion on this exact question, as well as several more related questions.
Thank you for understanding, and happy exploring!
GMAT Club Bot
gmatclubot
Re: What is the probability that exactly two of the six numbers appear on [#permalink]
12 Jan 2019, 10:33
Moderators:
Bunuel
Math Expert
92948 posts
yashikaaggarwal
Senior Moderator - Masters Forum
3137 posts

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne
Main navigation
GMAT Resources
Partners
MBA Resources
www.gmac.com|www.mba.com | | GMAT Club Rules | Terms and Conditions