There are 4 quarters and 3 dimes placed at random in a line. : Quant Question Archive [LOCKED]
Check GMAT Club Decision Tracker for the Latest School Decision Releases http://gmatclub.com/AppTrack

 It is currently 24 Jan 2017, 18:08

### 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

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

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# There are 4 quarters and 3 dimes placed at random in a line.

Author Message
Manager
Joined: 07 Jun 2006
Posts: 111
Followers: 2

Kudos [?]: 26 [0], given: 0

There are 4 quarters and 3 dimes placed at random in a line. [#permalink]

### Show Tags

15 Oct 2006, 10:14
This topic is locked. If you want to discuss this question please re-post it in the respective forum.

There are 4 quarters and 3 dimes placed at random in a line. The probability that the both extreme coins are dimes is

a) 1/4
b) 1/3
c) 1/7
d) 1/12
e) 1/2
Senior Manager
Joined: 08 Jun 2006
Posts: 340
Location: Washington DC
Followers: 1

Kudos [?]: 48 [0], given: 0

### Show Tags

15 Oct 2006, 10:26
I think it is 1 / 7

Explanation â€“

4 quarters are identical and 3 dimes are identical
4 quarters and 3 dimes can be placed in (4 + 3) ! / ( 4! * 3 !) ways = 35 ways

Consider extreme 2 corners are 2 dimes. Then the remaining coins are 4 quarters and 1 dimes.
4 quarters and 1 dime can be arranged in (4 + 1) ! / ( 4! * 1 !) = 5

So the probability is = (Possible 5 cases) / (total cases 35) = 1/7
Manager
Joined: 01 Oct 2006
Posts: 242
Followers: 1

Kudos [?]: 11 [0], given: 0

### Show Tags

15 Oct 2006, 10:28
yeah, I also get 1/7.
Manager
Joined: 08 Jul 2006
Posts: 89
Followers: 1

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

### Show Tags

15 Oct 2006, 11:00
1/7 too

D _ _ _ _ _ D

3P2 * 5P5
------------
7P7
Senior Manager
Joined: 05 Oct 2006
Posts: 267
Followers: 1

Kudos [?]: 17 [0], given: 0

### Show Tags

15 Oct 2006, 22:37
i think the qus is simply asking how to choose 2 quarters out of a total of 7 coins...and not about how other coins will be placed...

what u think??
15 Oct 2006, 22:37
Display posts from previous: Sort by