Find all School-related info fast with the new School-Specific MBA Forum
Learn more about the recent changes... close

It is currently 21 May 2013, 08:46
Customize  |  Hide

Search
Register
New posts
Unanswered

Which of the following fractions has a decimal equivalent

  Question banks Downloads My Bookmarks Reviews  
  Oldest Best Reply
Search for:
 
Print view
First unread post
Author Message
TAGS:
Director
Director
User avatar
Joined: 08 Jul 2004
Posts: 613
Followers: 1

Kudos [?]: 4 [0], given: 0

GMAT Tests User
Which of the following fractions has a decimal equivalent [#permalink] New post 25 Sep 2004, 16:02
00:00

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions
Which of the following fractions has a decimal equivalent that is a terminating decimal?
A 10/189
B 15/196
C 16/225
D 25/144
E 39/128
Intern
Intern
Joined: 22 Mar 2004
Posts: 25
Location: TX
Followers: 0

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

 [#permalink] New post 25 Sep 2004, 16:19
C.

cos any number ending with a 5 when used as a divisor, will result in a terminating decimal
Director
Director
User avatar
Joined: 31 Aug 2004
Posts: 619
Followers: 1

Kudos [?]: 8 [0], given: 0

GMAT Tests User
 [#permalink] New post 25 Sep 2004, 16:47
Longhorn,

Could you please elaborate on this ?
Do you have any theoretical explaination ?
Director
Director
Joined: 20 Jul 2004
Posts: 601
Followers: 1

Kudos [?]: 3 [0], given: 0

GMAT Tests User
 [#permalink] New post 25 Sep 2004, 17:28
Very good question.

I will choose E.
All other choices have a odd prime number in the denominator whereas E has only 2s.

Divide any number by an odd prime and it is going to be infinite. Anything with only 2s in denominator is finite; it either ends as a whole number or 0.5
Director
Director
User avatar
Joined: 08 Jul 2004
Posts: 613
Followers: 1

Kudos [?]: 4 [0], given: 0

GMAT Tests User
 [#permalink] New post 25 Sep 2004, 17:37
Yes, that is what I thought. 225 is 15 square has 3 in it. 128 is 2^7 , so always give 0.5. Others are square which has 3 and 189 has 7 to make non-terminating.
Cheers.
S
Director
Director
User avatar
Joined: 31 Aug 2004
Posts: 619
Followers: 1

Kudos [?]: 8 [0], given: 0

GMAT Tests User
 [#permalink] New post 27 Sep 2004, 02:49
Hardworker;

I agree with you : dividing any number with any odd prime will provide something unterminated.
What do you mean exactly by 2s ?
Manager
Manager
Joined: 26 Sep 2004
Posts: 145
Followers: 1

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

 [#permalink] New post 27 Sep 2004, 06:28
Hardworker , correct answer .. by the way longhorn guy yur theory is false :)
_________________

Franky
http://franky4gmat.blogspot.com

Director
Director
User avatar
Joined: 08 Jul 2004
Posts: 613
Followers: 1

Kudos [?]: 4 [0], given: 0

GMAT Tests User
 [#permalink] New post 27 Sep 2004, 06:31
No, i think Longhorn is right but in all cases 5 is compunded with 3 to make non terminating.
S
Manager
Manager
Joined: 26 Sep 2004
Posts: 145
Followers: 1

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

 [#permalink] New post 27 Sep 2004, 06:51
Any number terminating in 5 shall give a terminating decimal, this theory is false , exactly for the exception yu mentioned, and 3 is not just the only combination.
_________________

Franky
http://franky4gmat.blogspot.com

Intern
Intern
Joined: 25 Sep 2004
Posts: 24
Followers: 0

Kudos [?]: 1 [0], given: 0

Re: PS Any better way to this? [#permalink] New post 28 Sep 2004, 01:34
saurya_s wrote:
Which of the following fractions has a decimal equivalent that is a terminating decimal?
A 10/189
B 15/196
C 16/225
D 25/144
E 39/128



Any number that either only contains: 2 or powers of 2 in the denominator OR 5 or powers of 5 OR mixture of powers of 2 and 5 (for example: 20 (2^2*5) ) would be eligible as a terminating decimal.

Therefore answer in this case is E

I hope that helps!
Director
Director
User avatar
Joined: 31 Aug 2004
Posts: 619
Followers: 1

Kudos [?]: 8 [0], given: 0

GMAT Tests User
 [#permalink] New post 28 Sep 2004, 11:00
Linker,

I am not sure i understand your theory :

In case of your 2^n5^p denominator, what happens if numerator is a power of 3 ?? unterminated...
Intern
Intern
Joined: 25 Sep 2004
Posts: 24
Followers: 0

Kudos [?]: 1 [0], given: 0

 [#permalink] New post 29 Sep 2004, 05:34
twixt wrote:
Linker,

I am not sure i understand your theory :

In case of your 2^n5^p denominator, what happens if numerator is a power of 3 ?? unterminated...


Hi Twixt

Which of power 3 in the numerator is giving you an unterminated result, apply my conclusion to any number contaning anything in the numerator, but the denomiator should only have powers of 2 or powers of 5 or a mixture of powers 2 and 5. It holds for all nos.

Please examplify your point !
Director
Director
Joined: 20 Jul 2004
Posts: 601
Followers: 1

Kudos [?]: 3 [0], given: 0

GMAT Tests User
 [#permalink] New post 29 Sep 2004, 07:52
twixt wrote:
Linker,
I am not sure i understand your theory :
In case of your 2^n5^p denominator, what happens if numerator is a power of 3 ?? unterminated...


Yes. See examples below. I will take a common prime numerator, say 43.

43/32 -> terminating decimal -> Since it has only 2 as prime factor
43/625 -> terminating decimal -> Since it has only 5 as prime factor
43/50 -> terminating decimal -> Since it has only 2 and 5 as prime factors
43/150 -> not a terminating decimal -> Since it has 3 as a prime factor apart from 2 and 5
43/41 -> not a terminating decimal -> Since it does not have 2 or 5 as a prime factor.

I will rephrase my statement above: Any fraction with a denominator containing prime factors of only 2 and 5, will be have terminating decimal.
Director
Director
User avatar
Joined: 31 Aug 2004
Posts: 619
Followers: 1

Kudos [?]: 8 [0], given: 0

GMAT Tests User
 [#permalink] New post 30 Sep 2004, 08:11
Sorry linker my mistake !
I was confused by the choices and the added prime 3.

I tried this with various numbers and it works : thank you guys for this nice trick !
  [#permalink] 30 Sep 2004, 08:11
    Similar topics Author Replies Last post
Similar
Topics:
 New posts Which of the following fractions has a decimal equivalent crackgmat04 3 08 Dec 2004, 04:22
New posts Which of the following fractions has a decimal equivalent nocilis 6 04 Feb 2005, 22:42
New posts Which of the following fractions has a decimal equivalent sperumba 2 16 Jan 2006, 11:21
New posts Which of the following fractions has a decimal equivalent freetheking 3 21 Jul 2006, 20:56
New posts Which of the following fractions has a decimal equivalent apollo168 2 23 Aug 2006, 01:33
Display posts from previous: Sort by

Which of the following fractions has a decimal equivalent

  Question banks Downloads My Bookmarks Reviews  
Print view
First unread post

Moderators: Bunuel, VeritasPrepKarishma, IanStewart

Search for:


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

Powered by phpBB © phpBB Group and phpBB SEO

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®.

Main navigation

GMAT Resources

Partners

MBA Resources

www.gmac.com|www.mba.com