Find all School-related info fast with the new School-Specific MBA Forum

It is currently 27 Aug 2014, 11:32

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.

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

The side lengths of triangle ABC are such that AC > BC > AB.

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
2 KUDOS received
Intern
Intern
avatar
Joined: 17 Jan 2013
Posts: 37
Followers: 1

Kudos [?]: 3 [2] , given: 67

The side lengths of triangle ABC are such that AC > BC > AB. [#permalink] New post 11 Mar 2013, 14:13
2
This post received
KUDOS
00:00
A
B
C
D
E

Difficulty:

  25% (medium)

Question Stats:

69% (02:36) correct 31% (00:49) wrong based on 128 sessions
The side lengths of a right triangle ABC are such that AC > BC > AB. AC = 25 and AB = 9. What is the length of BC?

A. 16
B. 4\sqrt{34}
C. 41
D. 4\sqrt{52}
E. 256

[Reveal] Spoiler:
solution
Correct Answer: (B)

While this might appear to be a 3-4-5 triangle, you can’t square each side of a 3-4-5 and expect the pattern to hold: a 3-4-5 triangle must be some triangle whose sides can be reduced to the ratio 3x:4x:5x. As such, we have to resort to the Pythagorean Theorem, which in this case gives us 9^2+b^2=25^2, or b^2=544. At this point you can approximate – 544−−−√ is greater than 400−−−√, or 20, and less than 625−−−√, or 25, so the answer must be between 20 and 25: (B) the only such option.


---xx----

The query here isnt the answer to the problem but the solution given by veritas.. the way i deduced the answer was using the properties of triangle third side lies between the difference & sum of other two sides hence:
25-9<BC< 25+9
16<BC<34

and the only option falling is B. The explanation here says answer is between 20 and 25.. who is going wrong and where??

any help would be appreciated :)

Edited: Added 'right' to the question.
[Reveal] Spoiler: OA

Last edited by VeritasPrepKarishma on 13 Mar 2013, 19:11, edited 1 time in total.
The question was missing information.
Veritas Prep GMAT Discount CodesKnewton GMAT Discount CodesManhattan GMAT Discount Codes
Expert Post
1 KUDOS received
Veritas Prep GMAT Instructor
User avatar
Joined: 16 Oct 2010
Posts: 4687
Location: Pune, India
Followers: 1080

Kudos [?]: 4844 [1] , given: 163

Re: The side lengths of triangle ABC are such that AC > BC > AB. [#permalink] New post 11 Mar 2013, 20:04
1
This post received
KUDOS
Expert's post
swarman wrote:
The side lengths of triangle ABC are such that AC > BC > AB. AC = 25 and AB = 9. What is the length of BC?

16
4\sqrt{34}
41
4\sqrt{52}
256

[Reveal] Spoiler:
solution
Correct Answer: (B)

While this might appear to be a 3-4-5 triangle, you can’t square each side of a 3-4-5 and expect the pattern to hold: a 3-4-5 triangle must be some triangle whose sides can be reduced to the ratio 3x:4x:5x. As such, we have to resort to the Pythagorean Theorem, which in this case gives us 92+b2=252, or b2=544. At this point you can approximate – 544−−−√ is greater than 400−−−√, or 20, and less than 625−−−√, or 25, so the answer must be between 20 and 25: (B) the only such option.


---xx----

The query here isnt the answer to the problem but the solution given by veritas.. the way i deduced the answer was using the properties of triangle third side lies between the difference & sum of other two sides hence:
25-9<BC< 25+9
16<BC<34

and the only option falling is B. The explanation here says answer is between 20 and 25.. who is going wrong and where??

any help would be appreciated :)


I assume there is a diagram attached with it which gives some more information (that the triangle is a right triangle) etc. Also, judging from the question, we need to give the actual length of BC, not give the length that BC CAN take. Hence, there has to be some more info.

Given the limited info, your method is fine. Since 25 > BC > 9, the only possible options are (A) and (B). But sum of any two sides of a triangle must be greater than the third side so BC cannot be 16.
Answer (B)
_________________

Karishma
Veritas Prep | GMAT Instructor
My Blog

Save $100 on Veritas Prep GMAT Courses And Admissions Consulting
Enroll now. Pay later. Take advantage of Veritas Prep's flexible payment plan options.

Veritas Prep Reviews

Intern
Intern
avatar
Joined: 17 Jan 2013
Posts: 37
Followers: 1

Kudos [?]: 3 [0], given: 67

Re: The side lengths of triangle ABC are such that AC > BC > AB. [#permalink] New post 12 Mar 2013, 06:57
I so agree with you, but surprisingly no diagram was attached with it.. Thank you for clarifying my approach though :)
Expert Post
1 KUDOS received
Veritas Prep GMAT Instructor
User avatar
Joined: 11 Dec 2012
Posts: 313
Followers: 59

Kudos [?]: 185 [1] , given: 66

Re: The side lengths of triangle ABC are such that AC > BC > AB. [#permalink] New post 12 Mar 2013, 07:59
1
This post received
KUDOS
Expert's post
swarman wrote:
The side lengths of triangle ABC are such that AC > BC > AB. AC = 25 and AB = 9. What is the length of BC?

A. 16
B. 4\sqrt{34}
C. 41
D. 4\sqrt{52}
E. 256

[Reveal] Spoiler:
solution
Correct Answer: (B)

While this might appear to be a 3-4-5 triangle, you can’t square each side of a 3-4-5 and expect the pattern to hold: a 3-4-5 triangle must be some triangle whose sides can be reduced to the ratio 3x:4x:5x. As such, we have to resort to the Pythagorean Theorem, which in this case gives us 92+b2=252, or b2=544. At this point you can approximate – 544−−−√ is greater than 400−−−√, or 20, and less than 625−−−√, or 25, so the answer must be between 20 and 25: (B) the only such option.


---xx----


I really like this question, because a lot of students immediately think the answer must be 16 to maintain that 3-4-5 pattern they've heard so much about, but obviously that is the trap answer for those going too fast.

Once you've figured out that the Pythagorean Theorem will unlock the answer for you, the major hurdle is approximating square roots. This made me think of a blog I wrote on this topic a month or two back. It's actually perfect for exactly this question, so I figured I'd link it here in case it helped anyone:

http://www.veritasprep.com/blog/2013/02/ron-point/

Thanks!
-Ron
_________________

Ron Awad
Veritas Prep | GMAT Instructor
Save $100 on Veritas Prep GMAT Courses and Admissions Consulting Services
Veritas Prep Reviews

Expert Post
1 KUDOS received
Veritas Prep Representative
User avatar
Joined: 22 Apr 2004
Posts: 1103
Location: Southern California
Schools: Kellogg MBA 2004
Followers: 35

Kudos [?]: 209 [1] , given: 48

Re: The side lengths of triangle ABC are such that AC > BC > AB. [#permalink] New post 13 Mar 2013, 08:21
1
This post received
KUDOS
Expert's post
I agree... Great question, and great blog post, too!
_________________

Scott

Veritas Prep | GMAT Prep | MBA Admissions Consulting | Co-author, Your MBA Game Plan

Save $100 on Veritas Prep GMAT Courses And Admissions Consulting
For a limited time, receive access to five Veritas Prep Computer Adaptive practice tests when you purchase a Veritas Prep GMAT book! Buy Now!
Enroll now. Pay later. Take advantage of Veritas Prep's flexible payment plan options.

Veritas Prep Reviews

Manager
Manager
avatar
Joined: 24 Apr 2013
Posts: 75
Location: United States
Followers: 0

Kudos [?]: 6 [0], given: 23

Re: The side lengths of triangle ABC are such that AC > BC > AB. [#permalink] New post 18 May 2013, 06:07
I'm still having difficulty deciding between answer choices B and D

So I understand that the third side BC should be 16<BC<34

If I try to evaluate answer (B) 4sqt34 it gives 23.3 which is a possible answer. Also when I evaluate (D) 4sqt52 it gives 28.8 which is still a possible answer. I seem to be missing a trick.
Please help
_________________

Struggling: make or break attempt

Manager
Manager
User avatar
Joined: 24 Nov 2012
Posts: 161
Concentration: Sustainability, Entrepreneurship
GMAT 1: 770 Q50 V44
WE: Business Development (Internet and New Media)
Followers: 16

Kudos [?]: 80 [0], given: 73

Re: The side lengths of triangle ABC are such that AC > BC > AB. [#permalink] New post 19 May 2013, 04:10
There is a very simple way to solve this question. We know AC=25 , AB = 9 and assume BC = x

We also know that since it is a right triangle x^2 + 81 = 25^2

Now before embarking on lengthy calculations, it can easily be observed that for the equation x^2 should have the units digit as 4. By simple process of elimination and no lengthy calculations you can deduce that only option B fits the bill. (if x =4root34, x^2 units place = 4 since x^2 =16 x 34

Hope this makes sense
_________________

You've been walking the ocean's edge, holding up your robes to keep them dry. You must dive naked under, and deeper under, a thousand times deeper! - Rumi

http://www.manhattangmat.com/blog/index ... nprep-com/ - This is worth its weight in gold

Economist GMAT Test - 730, Q50, V41 Aug 9th, 2013
Manhattan GMAT Test - 670, Q45, V36 Aug 11th, 2013
Manhattan GMAT Test - 680, Q47, V36 Aug 17th, 2013
GmatPrep CAT 1 - 770, Q50, V44 Aug 24th, 2013
Manhattan GMAT Test - 690, Q45, V39 Aug 30th, 2013
Manhattan GMAT Test - 710, Q48, V39 Sep 13th, 2013
GmatPrep CAT 2 - 740, Q49, V41 Oct 6th, 2013

GMAT - 770, Q50, V44, Oct 7th, 2013
My Debrief - from-the-ashes-thou-shall-rise-770-q-50-v-44-awa-5-ir-162299.html#p1284542

Expert Post
Veritas Prep GMAT Instructor
User avatar
Joined: 16 Oct 2010
Posts: 4687
Location: Pune, India
Followers: 1080

Kudos [?]: 4844 [0], given: 163

Re: The side lengths of triangle ABC are such that AC > BC > AB. [#permalink] New post 19 May 2013, 08:04
Expert's post
SaraLotfy wrote:
I'm still having difficulty deciding between answer choices B and D

So I understand that the third side BC should be 16<BC<34

If I try to evaluate answer (B) 4sqt34 it gives 23.3 which is a possible answer. Also when I evaluate (D) 4sqt52 it gives 28.8 which is still a possible answer. I seem to be missing a trick.
Please help



Notice that the word 'right' had been added to the question. If it is a right triangle, you can easily use Pythagorean theorem and get your answer.

The original poster had tried to solve it for any generic triangle (the question without the word 'right').
You understand 16 < BC < 34.
Also, realize that you are given that AC > BC
Since AC = 25, BC must be less than 25. So only (B) works.
_________________

Karishma
Veritas Prep | GMAT Instructor
My Blog

Save $100 on Veritas Prep GMAT Courses And Admissions Consulting
Enroll now. Pay later. Take advantage of Veritas Prep's flexible payment plan options.

Veritas Prep Reviews

SVP
SVP
User avatar
Joined: 09 Sep 2013
Posts: 2188
Followers: 185

Kudos [?]: 36 [0], given: 0

Premium Member
Re: The side lengths of triangle ABC are such that AC > BC > AB. [#permalink] New post 28 Jul 2014, 21:26
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________

GMAT Books | GMAT Club Tests | Best Prices on GMAT Courses | GMAT Mobile App | Math Resources | Verbal Resources

Re: The side lengths of triangle ABC are such that AC > BC > AB.   [#permalink] 28 Jul 2014, 21:26
    Similar topics Author Replies Last post
Similar
Topics:
2 Experts publish their posts in the topic In triangle ABC above, what is the length of side BC? Bunuel 7 03 Mar 2014, 23:20
16 Experts publish their posts in the topic In triangle ABC above, what is the length of side BC? anilnandyala 13 21 Dec 2010, 07:17
AB BC and AC represent sides of a triangle ABC Is triangle Ozmba 6 09 Nov 2007, 08:12
If the length of side AB is 17, is triangle ABC a right a3d 12 24 Jul 2007, 18:06
In triangle ABC , the length of AB is 3 and the length of BC kevincan 5 14 Jul 2006, 03:03
Display posts from previous: Sort by

The side lengths of triangle ABC are such that AC > BC > AB.

  Question banks Downloads My Bookmarks Reviews Important topics  


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®.