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

It is currently 18 Jun 2013, 17:46
Customize  |  Hide

Search
Register
New posts
Unanswered

Tough Geometry problem

  Question banks Downloads My Bookmarks Reviews  
  Oldest Best Reply
Search for:
 
Print view
First unread post
Author Message
TAGS:
SVP
SVP
User avatar
Joined: 16 Nov 2010
Posts: 1719
Location: United States (IN)
Concentration: Strategy, Technology
Followers: 26

Kudos [?]: 229 [0], given: 35

GMAT Tests User Reviews Badge
Tough Geometry problem [#permalink] New post 16 Nov 2010, 22:03
00:00

Question Stats:

0% (00:00) correct 100% (00:20) wrong based on 1 sessions
Please help with this one :

A right angled triangle ABC was given in which angle C is 90 degrees. BC=4, AD=3. D is a point on BC. Given that the perimeter of triangle ABD is equal to the perimeter of triangle ADC. Then find the ratio BD/DC.
Intern
Intern
Joined: 18 Aug 2009
Posts: 41
Location: United States
Concentration: Finance, Entrepreneurship
Schools: Booth '14 (D), Sloan '14 (S), CBS '14 (D), Stern '14 (A), Johnson '14 (I)
GMAT 1: 740 Q49 V42
GPA: 3.29
WE: Engineering (Consulting)
Followers: 0

Kudos [?]: 11 [0], given: 4

Re: Tough Geometry problem [#permalink] New post 17 Nov 2010, 12:00
Since you posted this on PS forum, could you give the answer choices as well?
Intern
Intern
Joined: 18 Aug 2009
Posts: 41
Location: United States
Concentration: Finance, Entrepreneurship
Schools: Booth '14 (D), Sloan '14 (S), CBS '14 (D), Stern '14 (A), Johnson '14 (I)
GMAT 1: 740 Q49 V42
GPA: 3.29
WE: Engineering (Consulting)
Followers: 0

Kudos [?]: 11 [0], given: 4

Re: Tough Geometry problem [#permalink] New post 17 Nov 2010, 18:09
chaoswithin wrote:
Since you posted this on PS forum, could you give the answer choices as well?


The reason why I ask is because I can get a range for the possible answer, but not an exact number.

To get the upper limit, we can use the fact that the perimeters of the two triangles are equal and since they share the side AD, we can see that AB+BD = AC + DC

and since AB has to be > AC, BD has to be < DC so BD/DC has to be < 1.

for the lower limit, since AD = 3, DC has to be < 3. and since BD + DC = 4, when DC = 3 BD = 1 and BD/DC has to be > 1/3.

Therefore, 1/3 < BD/DC < 1. This is the best I can do with the givens.

If anyone else could shine some light on this problem, I would appreciate it.
SVP
SVP
User avatar
Joined: 16 Nov 2010
Posts: 1719
Location: United States (IN)
Concentration: Strategy, Technology
Followers: 26

Kudos [?]: 229 [0], given: 35

GMAT Tests User Reviews Badge
Re: Tough Geometry problem [#permalink] New post 18 Nov 2010, 04:26
The answer given was 1:3, I could not reckon how though !
_________________

Formula of Life -> Achievement/Potential = k * Happiness (where k is a constant)

Find out what's new at GMAT Club - latest features and updates

Intern
Intern
Joined: 18 Aug 2009
Posts: 41
Location: United States
Concentration: Finance, Entrepreneurship
Schools: Booth '14 (D), Sloan '14 (S), CBS '14 (D), Stern '14 (A), Johnson '14 (I)
GMAT 1: 740 Q49 V42
GPA: 3.29
WE: Engineering (Consulting)
Followers: 0

Kudos [?]: 11 [0], given: 4

Re: Tough Geometry problem [#permalink] New post 18 Nov 2010, 09:39
subhashghosh wrote:
The answer given was 1:3, I could not reckon how though !


This answer doesn't make sense.

Using the givens, the triangle should look similar to the triangle in the attachment.

In order for BD/DC to be 1/3, BD = 1 and DC = 3.

But since triangle ADC has hypotenuse AD = 3. DC cannot equal 3.

In order for BD/DC to be 1/3, the original question should be rephrased so AC = 3 instead of AD = 3.

If AC = 3.

AB = 5 (b/c the triangle becomes 345 triangle).

and we are left with two equations and two unknowns where

AB + BD = AC + DC and BD + DC = 4.

which results in BD = 1 and DC = 3.
Attachments

aa.JPG
aa.JPG [ 5.66 KiB | Viewed 689 times ]

Re: Tough Geometry problem   [#permalink] 18 Nov 2010, 09:39
    Similar topics Author Replies Last post
Similar
Topics:
 New posts DS: Tough Geometry (GMATPrep) mrmikec 2 18 Jun 2006, 13:06
New posts 2 Coordinate Geometry - Tough one FN 7 20 Jun 2008, 15:04
Popular new posts 2 Experts publish their posts in the topic Tough Geometry gmat620 18 01 Dec 2009, 12:01
This topic is locked, you cannot edit posts or make further replies. New 3 Experts publish their posts in the topic Tough Coordinate Geometry problem from the gmac test ksharma12 5 10 Jul 2010, 19:17
New posts 3 Geometry Tough bhandariavi 4 22 Mar 2011, 21:59
Display posts from previous: Sort by

Tough Geometry problem

  Question banks Downloads My Bookmarks Reviews  
Print view
First unread post

Moderators: VeritasPrepKarishma, Bunuel, 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