Last visit was: 02 Jan 2025, 22:18 It is currently 02 Jan 2025, 22:18
Decision Tracker
My Rewards
New comers' posts
New posts
Unanswered

Close

GRE Prep 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 GRE 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
PREVIOUS TOPIC
NEXT TOPIC

GRE Math Challenge #18- 4 mathematics and 5 physics books

Tags :
Find Similar Topics  About  Add a Tag

Show Tags
Hide Tags

User avatar
sandy
Retired Moderator
Joined: 07 Jun 2014
Posts: 4815
Own Kudos [?]: 11279 [0]
Given Kudos: 0
GRE 1: Q167 V156
WE:Business Development (Energy and Utilities)
Send PM
GRE Math Challenge #18- 4 mathematics and 5 physics books [#permalink] New post   09 Sep 2014, 03:11
Expert Reply
00:00

Question Stats:

66% (02:30) correct 33% (00:35) wrong based on 3 sessions

Hide Show timer Statistics

4 mathematics and 5 physics books are arranged in a row on a shelf at random. Find the probability that the books on the same subject will be put together.

Show: :: Answer
total no. of ways of arranging all 9 books= 9! =A
total no. of arranging books such that all books of one kind are together
= 4! * 5! * 2 = B

thus probability that all books of one kind are together = B/A
Prep Club for GRE Bot
gmatclubot
GRE Math Challenge #18- 4 mathematics and 5 physics books [#permalink]
09 Sep 2014, 03:11
Moderators:
adewale223
GRE Instructor
88 posts
bronaugust
GRE Forum Moderator
37 posts
BrushMyQuant
Moderator
1126 posts
VibhuAnurag
GRE Instructor
234 posts

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

Main navigation

Partners

GRE Resources

www.ets.org/gre | About | Terms and Conditions and Privacy Policy | Prep Club for GRE Rules | Contact